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Question 1 of 200

1.

A   30-year-old   patient  complains about   having   abdominal  pain   and   diarrhea for  five  days;  body  temperature rise  up  to  37, 5oC  along  with  chills. The day   before   a   patient  had   been   in   a forest and drunk from an open water reservoir.  Laboratory  analyses   enabled to make the following diagnosis: amebic dysentery. What  is the  drug of choice  for its treatment?

 

Explanation

Metronidazole forms toxic free radical metabolites in the bacterial cell that damage DNA. It is bactericidal, and an antiprotozoal. It is used to treat Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, Clostridium difficile). It can be used with a proton pump inhibitor and clarithromycin for “triple therapy” against Helicobacter pylori.

Entamoeba histolytica causes amebic dysentery.

2.

A man  suffering  from  a hereditary disease married a healthy  woman. They got 5 children,  three  girls and  two  boys. All the  girls inherited their  father’s  disease. What  is the  type  of  the  disease  inheritance?

Explanation

image

Autosomal dominant: often due to defects in structural genes. Many generations, both male and female are affected. Found in every generation; no generation is left out (skipped). Parent – child in every generation.

Autosomal recessive is usually seen in some generations (other generations are skipped).

It is sex linked, if only males or only females(X-linked) are affected.

Dominant because no generation was skipped(father-daughter). Only girls were affected, therefore it is X-linked (sex linked) because a father donates an x-chromosome to the daughter.

 father - XY;

mother - XX

  A father determines the gender of a child, if he gives an X-chromosome, then the child will be a female, and if he gives a Y-chromosome then the child will be a male.

3. An  electronic microphotograph shows a  macrophagic cell  with  erythrocytes at different stages of differentiation located along its processes.  This is the cell of the following organ:

Explanation

In an adult, erythrocyte, granulocytes, monocytes and platelets are formed in the red bone marrow (RBM); lymphocytes are also formed in the RBM and in the lymphatic tissues. Hemopoiesis (hematopoiesis) includes both erythropoiesis and leukopoiesis as well as thrombopioesis (development of platelets). Erythrocytes develop from the multipotential myeloid stem cell under the influence of erythropiotein. The erythropiotein-sensitive erythrocyte progenitor cells give rise to the first recognizable erythrocyte precursor, the proerythroblast.

Proerythroblast → basophilic erythroblast → polychromatophilic erythroblast → orthochromatophilic erythroblast (normoblast) → polychromatophilic erythrocyte (reticulocyte) → Erythrocyte.

       In normal blood, reticulocytes (new erythrocytes) constitute 1-2% of total erythrocyte count.

IMG_9922

4.

Quite  often the cause of secondary immunodeficiency is an infection involvement, when the causative agents propagate directly  in the cells of immune system  and  destroy  it. The  following  diseases are characterized by:

Explanation

IMG_9905          

Secondary immunodeficiency occur after full development of the immune system. Chronic virus infections (e.g. infectious mononucleosis caused by Epstein-Barr virus) and HIV (human immunodeficiency virus) may cause secondary immunodeficiencies. HIV → CD4 cells; Epstein Barr virus (EBV) → B lymphocytes (B cells).

5.

Examination  of  a  patient revealed   a dense, movable skin tumour that is standing out distinctly  from the surrounding tissues. Its section is found to be white and composed  of fibrous tissue. Microscopic examination revealed  interlacing collagen fibers and few cells. What tumour is it?

Explanation

Fibroma is a benign connective (fibrous) tissue tumors. It can be hard (dense) or soft fibroma. Hard fibroma has fibrous connective tissue (e.g. collagen fibers) prevail over the cellular elements. Soft/loose fibroma has more cells than the connective tissue component.

In the question; fascicles of divergent collagen fibers with SOME fusiform cells irregularly distributed among the fibers i.e. fibers > cells (fibers dominate).

6.

A patient underwent a surgery for excision of a cyst on pancreas.  After  this he developed haemorrhagic syndrome   with apparent disorder   of  blood  coagulation. Development of this complication can be explained by:

Explanation

Hemorrhagic syndrome can develop from surgery for excision of a cyst on pancreas. Pancreas contains inactive proteolytic enzymes which can be accidentally released during surgery on pancreas). Most of the clotting factors are proteins in the form of enzymes. Normally, all the factors are present in the form of inactive proenzyme which must be activated into enzymes by proteolytic enzymes. Likewise, in fibrinolysis plasmin is formed from inactivated glycoprotein called plasminogen..All these inactive enzymes can be activated, if the proteolytic enzymes and lysosomal enzymes specifically cathepsin with trypsinogen in pancreas are accidentally released during surgery. Cathepsin activates trypsinogen to trypsin leading to further activation of other molecules of trypsinogen and plasminogen can now be converted into its active form plasmin. This systemic activation of plasminogen into plasmin cause generalized fibrinolysis – removing blood clots.

7.

A mother consulted  a doctor  about  her 5-year-old  child who develops  erythemas, vesicular   rash  and  skin  itch  under   the influence    of   sun.   Laboratory   studies revealed  decreased iron  concentration in the  blood  serum,  increased  uroporphyrinogen  I excretion with the urine.  What  is the most likely inherited pathology  in this child?

Explanation

Erythropoietic porphyria (Gunther’s disease): This disorder is due to a defect in the enzyme Uroporphyrinogen III cosynthase. It is characterized by:

* It is a rare congenital disorder caused by autosomal recessive mode of inheritance, mostly confined to erythropoietic tissues.

* The individuals excrete Uroporphyrinogen I and Coproporphyrinogen I which oxidize respectively to Uroporphyrin I and Coproporphyrin I (red pigments).

* The patients are photosensitive (itching and burning of skin when exposed to visible light) due to the abnormal porphyrins that accumulate. Porphyrins are accumulated in the teeth, bones and an increases amount are seen in the plasma, bone marrow, faeces, RBCs and urine.

* Increased hemolysis is also observed in the individuals affected by this disorder.

8. A baby refuses the breast, he is anxious, presents with arrhythmic respiration. The urine smells of \\\"brewer’s yeast\\\" or \\\"maple syrup\\\".  This pathology  was caused by the inherited defect of the following enzyme:

Explanation

Maple syrup urine disease results from blocked degradation of branched amino acids (isoleucine, leucine, valine) due to decreased activity or deficiency of α-ketoacid dehydrogenase. It causes increase α-ketoacids in the blood, especially those of leucine. It also causes severe CNS defects, intellectual disability and death. It is an autosomal recessive disease. Urine smells like maple syrup/burnt sugar. Treatment: restriction of isoleucine, leucine, valine in diet and thiamine supplementation.

9. While  studying  a  microslide  obtained from  the  punctuate of a regional  lymph node and stained by Romanovsky-Giemsa method  a physician  revealed  some  light- pink   thin   microorganisms   with   12-14 regular  spiral  coils and  pointed ends,  up to 10-13 micrometer long. This might  be the  causative  agent  of  the  following  disease:

Explanation

Spirochetes are thin-walled, flexible, spiral rods. Three (3) genera of spirochetes cause human infection: Treponema (syphilis and the nonvenereal treponematoses); Borrelia (lyme disease and relapsing fever); Leptospira (leptospirosis). Treponema pallidum are thin, tight, spirals seen by darkfield illumination, silver impregnation or immunofluorescent stain.

Syphilis (lues) is a sexually transmitted disease of mankind caused by the spirochete – Treponema pallidum. Stages of syphilis are: primary (chancre); secondary (disseminated) and Tertiary (with lesions of deep organs following a latent period of 2 – 20 years or more).

The chancre develops at the site of inoculation in 10 – 90 days (average 21 days) and has a characteristic “luetic vasculitis” (endovasculitis, perivasculitis) in which endothelial cells proliferate and swell and the walls of the vessels become thickened by lymphocytes and fibrous tissue. Syphilis can also produce fibrinoid or caseous necrosis (gumma).

10.

Sanitary   bacteriological research  on water by the membrane filter method revealed  two red colonies on a membrane filter (Endo agar)  through which 500 ml of analyzed  water  were passed.  Calculate the coli index and coli titer of the analyzed water:

 

Explanation

Coli titer is the smallest amount of water where 1 E.coli is present.

Coli index is the amount of E. coli in 1 liter of water.

            2 E.coli   -  500ml

            1 E.coli   -  ?

                        ? = 250

Therefore, Coli titer = 250

 

1 liter of water  =  1000ml

            2 E. coli   -  500ml

                   ?       -   1000ml (1L)

                        ? = 4

Therefore, Coli index = 4

Coliform index (Coli index) and Coli titer are used to rate the purity of water, soil and air based on the count of fecal bacteria by testing for coliforms especially the well known Escherichia coli (E. coli).

11.

While examining  a patient an otolaryngologist noticed  hyperaemia and significantly edematous tonsils with a grayish film upon them. Microscopical examination of  this  film  revealed   some gram-positive bacilli  placed  at  an  angle with each other. What disease might be suspected?

Explanation

Diphtheria bacteria (Corynebacterium diphtheria) is Gram positive, pleomorphic, often club-shaped rods and are arranged in palisades or in V (at an angle) or L-shaped formations. Media used for isolation are Tellurite agar & Lὄffler medium. Lὄffler nutrient medium consists of coagulated serum & nutrient broth. Selective indicator medium containing tellurite are used in selective culturing. K tellurite is used to inhibit the accompanying flora.

12. A 38-year-old  patient with an uterine haemorrhage lasting  for 2 days was delivered to the admission ward. Which of the following will be revealed  in the patient’s blood?

Explanation

Hematocrit or packed cell volume (PCV) is the proportion of blood occupied by RBCs expressed in percentage. It is the volume of RBCs packed at the bottom of a hematocrit tube when the blood is centrifuged.

    * Increases in hematocrit can be seen in polycythemia, dehydration, dengue shock syndrome [Dengue fever (tropical disease caused by flavivirus transmitted by the mosquito Aedes aegypti) of grade III or IV severity]

    * Decrease in hematocrit can be seen in Anemia, Cirrhosis of liver, Pregnancy, Hemorrhage (which can be due to ectopic pregnancy).

13.

After    a   hypertonic  crisis   a   patient presents with lacking spontaneous movements  in  his  right   arm   and   leg, muscle  tone  of these  extremities is increased.  What  type of motor  dysfunction has developed in this case?

Explanation

Paralysis is the absence or decrease of muscular strength in limbs which makes movement impossible. It can be central or peripheral. Central paralysis caused by central motor neuron lesion, with symptoms such as spastic paralysis-muscular hypertonus (muscle tone), proprioceptive reflexes increase, absence of atropy. Peripheral paralysis caused by peripheral motor neuron lesions with symptoms such as atonic, flaccid paralysis-muscular atrophy and no reflexes.
14. A patient\\\'s organism has decreased concentration of magnesium ions that are necessary for attachment of ribosomes to the  granular endoplasmatic reticulum. It  is known  that  this  causes  protein biosynthesis disturbance. What stage of protein biosynthesis  will be disturbed?

Explanation

A large number of components are required for translation (synthesis of a protein). These include all the amino acids that are found in the finished product, the mRNA to be translated, tRNA, functional ribosomes, energy sources and enzymes as well as protein factors needed for initiation, elongation and termination of the polypeptide chain. In eukaryotic cells, the ribosomes are either “free” in the cytosol or are in close association with the endoplasmic reticulum (which is then known as the “rough” endoplasmic reticulum or RER). The RER – associated ribosomes are responsible for synthesizing proteins that are to be exported from the cell as well as those that are destined to become integrated into plasma, endoplasmic reticulum or golgi membranes or incorporated into lysosomes.

15.

A patient suffering from stomach ulcer has  been  treated with  an  antacid   drug almagel. For acute bronchitis treatment he was prescribed the  antibiotic methacycline.   However    within   next   5  days   the fever   didn’t   fall,   cough    and    sputum nature  remained unchanged. A  physician came to the  conclusion  that  the  drugs were incompatible. What type of drug incompatibility is the case?

Explanation

     Pharmacokinetics refers to what the body does to a drug. Once a drug is administered through one of several available routes, 4 pharmacokinetic properties determine the speed of onset of drug action, intensity of the drug’s effect and the duration of drug action: absorption, distribution, metabolism and elimination.

Absorption: first, drug absorption from the site of administration permits entry of the therapeutic agent (either directly or indirectly) into plasma. Absorption is the transfer of a drug from its site of administration to the bloodstream via different mechanisms.

Methacycline is a tetracycline. All tetracyclines are adequately absorbed after oral ingestion. However, taking these drugs concomitantly with diary foods in the diet decreases absorption due to the formation of nonabsorbable chelates of the tetracyclines with calcium ions. Nonabsorbable chelates are also formed with other divalent and trivalent cations e.g. those found in magnesium and aluminum antacids and in iron preparations. This presents a problem if a patient self-treats the epigastric upsets caused by tetracycline ingestion with antacids.

Nonforming CO2 antacids: aluminum hydroxide + magnesium hydroxide = Almagel or Maalox.

16. A 70-year-old  patient suffers from atherosclerosis complicated by the  lower limb thrombosis that has caused gangrene on  his left  toes.  What  is the  most  likely cause of the thrombosis origin?

Explanation

Atherosclerosis is a multifactorial disease that affects the intima of elastic arteries. Pathogenesis of atherosclerosis has 3 stages: 

   * Endothelial injury is accompanied by attachment of monocytes, platelets and thrombus formation.

   * Macrophages in the intima phagocytize lipid and transform into foam cells. Macrophages also secrete growth factors that stimulate the proliferation of smooth muscle cells.

   * Ruptured atheromas release thrombogenic material into the circulation causing thrombus for intimal ulceration.

17.

ECG  of  a  44-year-old  patient shows signs  of  hypertrophy  of  both   ventricles and the right atrium.  The patient was diagnosed  with the tricuspid  valve insufficiency. What pathogenetic variant of cardiac dysfunction is usually observed in case of such insufficiency?

Explanation

       Due to incomplete closure of the tricuspid valve during right ventricular systole, part of blood is regurgitated into the right atrium, where it is mixed with the normal volume of blood delivered from the venae cavae which makes the atrium become distended and hypertrophied. During diastole, a larger volume of blood is delivered into the right ventricle because the portion of blood that was regurgitated into the atrium during systole is added to the normal volume of blood delivered → ↑volume (heart overload). This causes dilatation and hypertrophy of the right ventricle. Compensation in this disease is attained by intensified work of left ventricle which leads to its hypertrophy too. The mass of the circulating blood usually increase proportionally to the degree of circulatory insufficiency. This is favored by retention of sodium chloride and water in decreased renal filtration and increased reabsorption of sodium and the increasing number of RBCs (hypoxia is attended by intensified hemopoiesis to compensate for the developing insufficiency) → ↑blood volume.

18.

Bacteriological  examination  of purulent discharges  from the urethra revealed  gram-negative bacteria looking like  coffee  beans.   They  were  localized in the leukocytes  and could decompose glucose and maltose to acid. These are the causative agents of the following disease:

Explanation

Gonorrhea is caused by Neisseria gonorrhoeae. Its often intracellular (within neutrophils), gram-negative diplococci.  It is sexually or perinatally transmitted.

Syphillis is caused by Treponema pallidum(spirochetes),  Chancroid is caused by Haemophilus ducreyi. Trichonomoniasis is caused by trichomonas vaginalis. Veneral lymphogrnaulomatosis is caused by Chlamydia trachomatis (L1-L3).

They are all sexually transmitted.  Specific identification of the gonococcus can be made either by its fermentation of glucose (but not maltose) or by fluorescent-antibody staining.

19.

Proserin increases skeletal muscle tone when given systematically. Halothane induces   relaxation  of  skeletal   muscles and   reduces   proserin  effects.   What   is the nature of proserin and halothane interaction?

Explanation

     Proserin (Neostigmine) is an indirect acting cholinergic agonist (anticholinesterase). It preserves endogenous acetylcholine which can stimulate a greater number of acetylcholine receptors at the muscle endplate. Halothane, on the other hand, is a general anesthetic that breaks neurotransmission. Proserin stimulates and aids neurotransmission, while halothane breaks neurotransmission (antagonism). This is done indirectly because they don’t act by the same mechanism to antagonize each other. It is functional because each drug weakens the other’s action/effect.

20.

A 62-year-old  female patient has developed a cataract (lenticular opacity) secondary  to the  diabetes  mellitus.  What type  of protein modification  is observed in case of diabetic  cataract?

Explanation

Microvascular complications of Diabetes Mellitus:

* Eye: retinopathy, cataracts, glaucoma

* Kidney: nephropathy - kidney failure, microalbuminuria, gross albuminuria

* Nerves: neuropathy - peripheral autonomic

There are 3 main metabolic pathways in the pathogenesis of chronic complications of DM:

        * Non enzymatic glycosylation

        * Intracellular hyperglycemia

        * Activation of protein kinase C

Nonenzymatic glycosylation: Glucose binds to the amino groups of proteins [reflected in glycosylated hemoglobin A (HbA1c)], repetitive glycosylation eventually results in cross-linking of proteins leading to dysfunction. These products accumulate in vessel walls (e.g. blood vessels of the eye). Glycosylation also occurs with lipids and nucleic acids.

21.

Examination of a 2-year-old  child revealed  physical  developmental lag, the child  often   has  pneumonias.  The  child was diagnosed  with nonclosure of ductus arteriosus. Haemodynamics disorder  was caused  by the  intercommunication of the following vessels:

Explanation

krushkrok No21 (2009)

As far as the lungs in fetus are inactive, the pulmonary arteries receive but little blood; so the greater portion of the venous blood that enters the pulmonary trunk drains to the aorta via wide ductus arteriosus (botallo’s duct). The duct connects the bifurcation of the pulmonary trunk to the concave portion of the aortic arch. Nonclosure of ductus arteriosus – Patent ductus arteriosus: In this case, the aorta (with relatively high blood pressure maintained) shunts the blood to the pulmonary trunk via the patent ductus arteriosus. This results in pressure increase within the pulmonary route and hypertrophy of both ventricles. This excessive shunting causes blood deficiency in the descending aorta and reduced blood supply to related organs. This in turn leads to marked growth retardation in children.

22.

The temperature of the ambient environment is 38oC and relative  air humidity is 50%. What ways of heat emission provide maintaining a constant temperature of the human  body?

 

Explanation

Evaporation is a way the body dissipates heat to the environment by its evaporation via sweat or evaporation of moisture from the skin and respiratory tract mucous membranes of (“wet” heat loss). Evaporation closely related to relative humidity.

Heat Radiation is a way the surface of the human body emits heat to the environment in the form of infrared rays. The amount of heat the body radiates to the environment is proportional to the surface of radiation area and to the difference between the mean values of skin and environment temperature. The surface radiation area is the total surface area of body parts that contact the air. Elimination of heat by radiation increases with a decrease in ambient temperature and decreases with its increase. It is possible to reduce elimination of heat by radiation via reduction of the surface of radiation area (“winding oneself into a ball”). Heat radiation does not require a medium for transfer of heat. (Key words: naked or lightly clothed).

Convection is a way the body eliminates heat by means of transferring heat via moving particles of air or water. To dissipate heat by means of convection, body surface shall be airflowed at a temperature that is lower than the temperature of the skin. At that, air layer contacting with the skin warms up, decreases its density, rises and is replaced by cooler, denser air. By increasing the speed of the air flow (wind, ventilation) heat emission increases significantly as well (forced convection). Convection requires convection current; current of gases or liquids (Key words: air over exposed area of skin).

Conduction is a way the body eliminates heat by means of direct contact with another object. Heat is transferred down the temperature gradient (i.e. from the object of higher temperature to the object of lower temperature). Conduction requires contact with another object (Key words:  in water).

23. A  married couple  consulted  a specialist at the genetic consultation about probability of having children  with hemophilia. Both spouses are healthy,  but the  wife’s father  has  hemophilia. In  this  family hemophilia may be passed to:

Explanation

Hemophilia is a group of sex-linked inherited blood disorders characterized by prolonged clotting time. However, the bleeding time is normal. Usually, it affects the males, with the females being the carriers. Hemophilia occurs due to lack of formation of prothrombin activator. That is why the coagulation time is prolonged. The formation of prothrombin activator is affected due to the deficiency of factors VIII, IX or XI.

   Types of hemophilia: 

*Hemophilia A or classic hemophilia - deficiency of factor VIII (X-LINKED RECESSIVE)

*Hemophilia B or Christmas disease - deficiency of factor IX (X-LINKED RECESSIVE)

*Hemophilia C or factor XI deficiency (AUTOSOMAL RECESSIVE)

It will be passed to the sons – the mother is the carrier.

24. The minute  blood volume in a patient with transplanted heart  has increased  as a result  of physical  activity.  What  regulative mechanism  is responsible for these changes?

Explanation

      A transplanted heart is denervated, so no nervous stimulation can increase or decrease the heart rate or cardiac output. Therefore, the only mechanism capable of increasing minute blood volume is the catecholamines (epinephrine/adrenaline; norepinephrine/noradrenaline).

25.

A    female    patient   consulted     a physician  about   digestive  disorder, extended abdominal pain. Examination revealed  drastic  decrease in hemoglobin concentration. It is known from the anamnesis that while living in the Far East the patient used to eat freshly-salted caviar. Some relatives  living with her had the similar condition. What  is the most likely diagnosis?

Explanation

·        Diphyllobothrium latum causes diphyllobothriasis. A fish tapeworm. In contrast to the other cestodes, which have suckers , the scolex of D. latum has two elongated sucking grooves by which the worm attaches to the intestinal wall. Infection by D. latum causes little damage in the small intestine. In some individuals, megaloblastic anemia occurs as a result of vitamin B12 deficiency caused by preferential uptake of the vitamin by the worm. Transmission: ingestion of larvae from raw freshwater fish. Caviar is prepared from fish.

·        Echinococcus granulosus causes Echinococcosis. It is composed of a scolex and only 3 proglottids, making it one of the smallest tapeworms. The scolex has a circle of hooks and 4 suckers similar to Taenia solium. Dogs are the most important definitive hosts. The intermediate hosts are usually sheep. Humans are almost always dead-end intermediate hosts. Transmission: ingestion of eggs from dog faeces. Disease – hydatid cysts in liver causing anaphylaxis if antigens released.

·        Taeniasis: there are two important human pathogens in the genus Taenia: T. solium (pork tapeworm) and T. saginata (beef tapeworm)

·        Trichiniasis (Trichinosis) is caused by Trichinella spiralis (nematode- roundworm). Transmission: fecal-oral; undercooked meat (especially pork). A few days after eating undercooked meat, usually pork, the patient experiences diarrhea followed by 1-2weeks later by fever, muscle pain, periorbital edema and eosinophilia.

·        Ascaridiasis (Ascariasis) caused by Ascaris lumbricoides (giant roundworm). The major damage occurs during larval immigration rather than from the presence of the adult worm in the intestines. The principal sites of tissue reaction are the lungs, where inflammation with an eosinophilic exudates occurs in response to larval antigens. Ascaris pneumonia with fever, cough and eosinophilia can occur with a heavy larval burden.

26.

A man has normal  sensitivity of his finger  skin,  however  he  doesn’t sense  his wedding ring around the finger. What process  induced   by  wearing  of  the  ring has caused this phenomenon?

Explanation

Adaptation is the decline in discharge of sensory impulses when a receptor is stimulated continuously with constant strength. It is also called sensory adaptation or desensitization. The ring has stimulated the receptors continuously with a constant strength for a long time and the receptors adapt.

27.

It is necessary  to take  the cerebrospinal  fluid  from  a  patient with  suspected inflammation of brain  tunics.  Diagnostic puncture was performed between the arches  of  the  lumbar   vertebras. During the puncture the needle  went through the following ligament:

Explanation

image

Ligamentum flava resides between the vertebral arches and consist of yellow elastic tissue. The clefts between the vertebral arches are covered by the ligamentum flava, which is the widest in the lumbar region. Therefore, these regions are used for the punctures of the vertebral canal to access the subarachnoid space. This procedure is actually performed on the L2 and L3 as well between the L3 and L4. Moreover, the puncture is also performed between the occipital bone and the first cervical vertebra piercing the atlanto-occipital membrane. In the thoracic region, the spinous processes overlap each other like a tile covering the arches of the lower vertebrae.

28.

ECG  study  showed  that  the  T -waves were  positive  in  the  standard extremity leads, their  amplitude and  duration were normal.   The  right  conclusion   would  be that  the  following  process  runs  normally in the heart  ventricles:

Explanation

krushkrok No28 (2009)      

 ‘T’ wave is the final  ventricular complex and is a positive wave. It is due to the repolarization of ventricular musculature. Normal duration is 0.2sec; normal amplitude is 0.3mV.

29.

A  patient has  an  increased pyruvate concentration in blood.  A  large  amount of it is excreted with the  urine.  What  vitamin is lacking in this patient?

Explanation

        Thiamine (vitamin B1): thiamine pyrophosphate (TPP) is the biologically active form of the vitamin, formed by the transfer of a pyrophosphate group from ATP to thiamine. Biological role of TPP: it is a component of pyruvate dehydrogenase and α-ketoglutarate dehydrogenase complexes catalyzing the reactions of oxidative decarboxylation of pyruvate and α-ketoglutarate (kreb’s cycle) i.e. it promotes energy formation from carbohydrates and lipids. It’s also a component of transketolase (pentose phosphate pathway of glucose oxidation) essential for fats and nucleic acids synthesis.

Pyruvate to acetyl CoA + CO2 reaction

            If pyruvate dehydrogenase cannot function properly due to vitamin B1 deficiency, then pyruvate will be accumulated in blood because it can’t be broken down.

30.

A patient has pellagra.  Interrogation revealed  that he had lived mostly on maize for a long time  and  eaten  little  meat. This disease had been caused by the deficit of the following substance  in the maize:

Explanation

Vit. B3 (Niacin, PP): coenzyme forms NAD+, NADP+ is derived from tryptophan. Synthesis requires Vit. B2 and B6. Vitamin B3 (niacin) is very high in fish and meat products.

 Pellagra results in vitamin B3 deficiency. Vit. B3 can also be called pellagra preventing.

31.

Study of bacteriological sputum  specimens stained  by the Ziel-Neelsen method revealed  some bright-red acid-resistant bacilli that were found in groups or singularly. When inoculated onto  the nutrient media, the signs of their growth show up on the 10-15 day. These bacteria relate to the following family:

Explanation

Mycobacteria are aerobic, acid fast bacilli (rods). They are neither gram +ve nor  gram -ve i.e. they are stained poorly by the dyes used in gram stain. They are virtually the only bacteria that are acid-fast (one exception is Nocardia asteroids, the major cause of Nocardiosis, which is also acid-fast). The term  “acid-fast” refers to an organism’s ability to retain the carbolfuchsin stain despite subsequent treatment with an ethanol-hydrochloric acid mixture. The high lipid content (approx. 60%) of their cell wall makes Mycobacteria acid-fast.The major pathogens are Mycobacterium tuberculosis, the cause of tuberculosis and Myobacterium lepra, the cause of leprosy. M. tuberculosis grows slowly. Its cell wall contains long chain (C78-C90) fatty acids called mycolic acids, which contribute to the organism’s acid-fastness. Ziehl-Neelsen stain is also known as acid-fast stain.

32.

A patient with high rate of obesity was advised to use carnitine as a food additive in order  to enhance \"fat  burning\". What is the role of carnitine in the process of fat oxidation?

Explanation

image

The major pathway for catabolism of saturated fatty acids is a mitochondrial pathway called β-oxidation. After a long-chain fatty acid (LCFA) enters a cell, it is converted in the cytosol to its Co-A derivative. Because β-oxidation occurs in the mitochondrial matrix, the fatty acid must be transported across inner mitochondrial membrane which is impermeable to Co-A. therefore, a specialized carrier transports the long chain acyl group from the cytosol into the mitochondrial matrix. This carrier is carnitine and this rate-limiting transport process is called the carnitine shuttle. Since carnitine helps the mitochondria utilize energy, it plays a critical role in reducing the occurrence and impact of obesity. In addition to helping the mitochondria burn fat as energy, carnitine is also vital for removing waste products from mitochondria. Obesity and aging contribute to low carnitine levels, which compromises mitochondrial performance and increases insulin resistance, promoting further obesity and carnitine reduction.

33.

In  a  2-year-old  child  with  catarrhal presentations  and  skin  rash  a  pediatrician  suspected   scarlet   fever.   The   child was given  intracutaneously a small  dose of  serum  antibody to  the  streptococcal erythrogenic toxin; on the site of injection the rash disappeared. What do the reaction results mean?

 

Explanation

For the rash to disappear it shows that the serum antibody injected is specific for the Streptococcal erythogenic toxin, which is a positive result. This shows that the antibody was specific and was able to react with the antigen (Streptococcal erythrogenic toxin), therefore the diagnosis was confirmed.

 

34.

A  patient has  a  transversal laceration in the spinal cord. What respiratory changes will result from this?

Explanation

35. A female  patient suffering  from bronchial  asthma  had  got a viral infection  that  provoked status  asthmaticus with fatal  outcome.  Histological  examination of lungs revealed  spasm and edema  of bronchioles, apparent infiltration  of their walls with  lymphocytes,  eosinophils   and other   leukocytes;   labrocyte   degranulation.  What  mechanism  of hypersensitivity underlies the described  alterations?

Explanation

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Type I (Immediate, Anaphylaxis, Reagin): IgE (immunoglobulin E)-dependent activation of mast cells/basophils, usually accompanied by eosinophilia e.g. urticaria (hives), hay fever, asthma (wheezing), rhinitis and conjunctivitis (stuffy nose and itchy eyes; usually seasonal)

36.

In  the  perianal  folds  of a 5-year-old girl her mother has found some white \\\"worms\\\" that caused  itch  and  anxiety  in the  child.  The  \\\"worms\\\" were sent  to  the laboratory. During examination the physician saw white filiform helminths 0,5-1 cm long, with pointed ends,  some  helminths had twisted ends. What  is the most likely diagnosis?

 

Explanation

Enterobius vermicularis causes pinworm infection (enterobiasis). The life cycle is confined to humans. The infection is acquired by ingesting the worm eggs. Perianal pruritus is the most prominent symptom. Pruritus is thought to be an allergic reaction to the presence of either the adult female or the eggs. Scratching predisposes to secondary bacterial infection. In Laboratory diagnosis, the eggs are recovered from perianal skin by using the scotch tape technique and can be observed microscopically. Unlike those of other intestinal nematodes, these eggs are not found in the stools. There are no means of prevention. It is treated with mebendazole.

37.

Examination of a 27-year-old  patient revealed  pathological changes in liver and brain.  Blood  plasma  analysis revealed  an abrupt decrease in the copper concentration, urine analysis revealed an increased copper  concentration. The patient was diagnosed  with  Wilson’s degeneration. To confirm  the  diagnosis  it  is necessary   to study the activity of the following enzyme in blood serum:

Explanation

Wilson’s disease is an inherited disorder characterized by excess of copper in the body tissues. It is also known as progressive hepatolenticular degeneration. This disease develops due to damage of the lenticular nucleus particularly the putamen.

      Pathogenesis: gene mutation - defective hepatocyte transport of copper into bile for excretion. Defective incorporation of copper into ceruloplasmin (binding protein for copper in blood). Unbound copper eventually accumulates in blood. Copper is loosely attached to albumin. Copper deposits in other tissue causing a toxic effect. The gene defect in Wilson’s disease affects a copper transport system that produces a dual defect - decreased incorporation of copper into ceruloplasmin in the liver (ceruloplasmin is decreased) and decreased excretion of copper into bile (intrahepatic copper is increased).

image

Kayser-Fleischer ring can be seen in the cornea of eye.

38.

A  patient complains  about   dyspnea provoked by  the  physical  activity.  Clinical examination revealed  anaemia and presence of the  paraprotein in the  zone of gamma-globulins. To confirm the myeloma  diagnosis it is necessary  to determine the following index in the patient’s urine:

Explanation

1.     Paraprotein, myeloma protein, M protein or spike protein is an abnormal immunoglobulin (Ig) fragment or immunoglobulin (Ig) light chain that is produced in excess by an abnormal clonal proliferation of plasma cells, typically in multiple myeloma. Monoclonal free light chains in the serum or urine are called bence jones (BJ) proteins.

Bence jones (BJ) protein: free kappa (κ) or lambda (λ) light chains that are excreted in urine associated with plasma cell malignancies (myeloma) and Waldenstrὄm macroglobulinemia. In myeloma, urinalysis for BJ protein is positive in 60-80% of cases.

39. After    a   serious   psycho-emotional stress  a 45-year-old  patient suddenly  felt constricting  heart  pain  irradiating to  the left  arm,  neck  and  left  scapula.  His face turned pale,  the  cold sweat stood  out  on it. The  pain  attack  was stopped with nitroglycerine. What process has developed in this patient?

Explanation

FullSizeRender (34)

Angina pectoris (stenocardia) is a characteristic sudden, severe, pressing chest pain radiating to the neck, jaw, back and arms. It is caused by coronary blood flow that is insufficient to meet the oxygen demands of the myocardium leading to ischemia. The imbalance between oxygen delivery and utilization may result during exertion (stress), from a spasm of the vascular smooth muscle or from destruction of blood vessels caused by atherosclerotic lesions. Quick removal of pain after taking nitroglycerin suggests angina pectoris (stenocardia).

40. A 62-year-old female patient complains about  frequent pains  in the  region  of thorax and vertebral column, rib fractures. A physician suspected myelomatosis (plasmocytoma). Which  of the  following laboratory indices  will be of the  greatest diagnostic importance?

Explanation

1.     Paraprotein, myeloma protein, M protein or spike protein is an abnormal immunoglobulin (Ig) fragment or immunoglobulin (Ig) light chain that is produced in excess by an abnormal clonal proliferation of plasma cells, typically in multiple myeloma. Monoclonal free light chains in the serum or urine are called bence jones (BJ) proteins.

Bence jones (BJ) protein: free kappa (κ) or lambda (λ) light chains that are excreted in urine associated with plasma cell malignancies (myeloma) and Waldenstrὄm macroglobulinemia. In myeloma, urinalysis for BJ protein is positive in 60-80% of cases.

Myeloma/Plasmocytoma/Multiple Myeloma

41.

An   8-year-old   child   was  admitted to  the  infectious  department with  fever (up  to  38oC )  and  punctuate  bright-red skin  rash.  The  child  was  diagnosed  as having scarlet  fever. Objectively:  mucous membrane of pharynx  is apparently hyperaemic and edematic,  the  tonsils are enlarged and have dull yellowish-grey foci with some black areas.  What  inflammation is the  reason  for the  pharynx  alterations?

Explanation

Scarlet fever is one of the forms of streptococcal infection. It is an acute infectious disease accompanied by local inflammatory changes mainly in the pharynx and typical generalized rash. A punctuate erythematous rash that is most abundant over the trunk and inner aspects of the arms and legs manifests exanthema. The face is also involved, but usually a small area about the mouth (nasolabial triangle) remains relatively unaffected to produce a circumoral pallor. Primary scarlatinic affect is characterized by catarrhal or necrotic tonsillitis:

·        Catarrhal tonsillitis is manifested by hyperemia of pharynx (flaring pharynx or burning faucet) with involvement of oral cavity and tongue. It presents a strawberry appearance because of the erythematous papillae that project from a gray-coated background. When peeling occurs, the tongue becomes beefy or crimson red and glistening.

·        Necrotic tonsillitis is characterized by coagulative necrosis and ulceration. Microscopically, there is a characteristic acute, edematous, neutrophilic (purulent) inflammatory reaction within the affected tissues, mostly affecting the soft palate, pharynx, auditory tube.

42.

Nappies  of a newborn have dark spots being  the  evidence  of homogentisic acid formation. This is caused by the metabolic disorder  of the following substance:

Explanation

image

Congenital deficiency of homogentisate oxidase (homogentisic acid oxidase) in the degradative pathway of tyrosine to Fumarate → pigment-forming homogentisic acid accumulates (homogentisuria) in tissues. Autosomal recessive. Usually benign. Urine turns black on prolonged exposure to air. May have debilitating arthralgias (homogentisic acid toxic to cartilage).

43.

A  histological   specimen   presents a receptor zone  of a sensoepithelial sense organ.  Cells of this zone are placed  upon the basal membrane and include the following types: external and internal receptor cells, external  and internal phalangeal cell, stem cells, external  limiting cells and external supporting cell. The described   receptor zone  belongs  to  the following sense organ:

Explanation

image

Organ of corti is the receptor organ for hearing. Organ of corti is made up of sensory elements called hair cells and various supporting cells. Cells of organ of corti are: inner and outer hair cells (external and internal receptor cells); external and internal phalangeal cells; external limiting cells (cells of Hensen); cells of Claudius.

44.

A patient was admitted to the  hospital   with   an   asphyxia   attack   provoked by a spasm of smooth muscles of the respiratory tracts.  This  attack   was  mainly caused  by alterations in the following parts of the airways:

Explanation

Trachea → main (primary or large) bronchi → lobar (secondary or median) bronchi → segmental (tertiary or small) bronchi → bronchioles (terminal bronchiole → respiratory bronchiole) → alveoli.

As the bronchi decrease in size because of branching, the cartilage plates become smaller and less numerous. The second change observed in the wall of the intrapulmonary bronchus is the addition of smooth muscle to form a complete circumferential layer. The smooth muscles become an increasingly conspicuous layer as the amount of cartilage diminishes. The muscularis layer is more attenuated and loosely organized in smaller bronchi where it may appear discontinuous because of its spiral course. Since the muscular layer is more in the smaller bronchi, it therefore means that bronchospasm will be more pronounced in the small bronchi.

45.

While   eating   a   child   choked    on food   and   aspirated  it.   The   child   has severe cough, cyanotic skin and mucous membranes, rapid pulse, infrequent respiration,   prolonged  expiration.  The  child has  developed the  following  disorder of the external  respiration:

Explanation

Asphyxia is the condition characterized by combination of hypoxia and hypercapnea due to obstruction of air passage. Effects of asphyxia develop in 3 stages: stage of hyperpnea, convulsions and collapse. Hyperpnea is the first stage of asphyxia. It extends for about 1min. In this stage, breathing becomes deep and rapid. It is due to the powerful stimulation of respiratory centers by excess CO2 (cyanotic skin and mucous membranes). Hyperpnea is followed by dyspnea and cyanosis. Eyes become more prominent. The aspiration interferes with normal air passage from the alveoli and the expiration becomes difficult producing expiratory dyspnea.

46.

A    50-year-old    patient   complains about   general   weakness,   appetite  loss and  cardiac  arrhythmia. The  patient presents with muscle hypotonia, flaccid paralyses,   weakened  peristaltic  activity of  the  bowels.  Such  condition might  be caused by:

Explanation

Hypokalemia (serum K+ <3.5mEq/L), can be caused by gastrointestinal or renal loss, decreased intake etc. Clinical and laboratory findings include: muscle weakness and fatigue (most common complaints); arrhythmia; ECG shows ‘U’ wave; polyuria etc. Muscle weakness (muscle hypotonia, flaccid paralysis and weakened peristaltic activity of the smooth muscles of the bowels).

47.

While  playing  volleyball  a sportsman jumped    and   then    landed    across   the external  edge  of  his  foot.  This  caused acute  pain  in the  talocrural articulation, active movements became limited, passive movements remained unlimited  but  painful. In the  region  of the  external ankle a swelling appeared, the  skin turned red and  became  warmer  to  the  touch.  What type of peripheral circulation  disorder  has developed in this case?

Explanation

Hyperemia or active hyperemia or arterial hyperemia is the term used for the increased volume of blood in the arterial or arteriolar vessels. It is caused by an increased supply of blood from arterial system. The affected tissue or organ is pink or red in appearance (erythema) and warm to the touch.

     Venous or passive hyperemia also known as congestion; the affected tissue or organ is cold to the touch.

48.

A  patient suffering  from  myasthenia has been  administered proserin. After  its administration the patient has got nausea, diarrhea, twitch  of  tongue   and  skeletal muscles. What  drug  would  help  to eliminate the intoxication?

Explanation

     Neostigmine/proserin reversibly inhibits anticholinesterase, an indirect acting cholinergic agonists. It is used symptomatically to treat myasthenia gravis. Proserin does not cause CNS side effects and is not used to overcome toxicity of central acting antimuscarinic agents.

Atropine is an antimuscarinic agent and is used for the treatment of overdoses or intoxication of cholinesterase inhibitor (proserin, physostigmine) and some types of mushroom poisoning (certain mushrooms contain cholinergic substances that block cholinesterases). It also blocks the effects of excess acetylcholine resulting from acetylcholinesterase inhibitors.

Physostigmine and pyridostigmine bromide are acetylcholinesterase inhibitors and will further synergize proserine.

Mesaton is an α-adrenergic agonists (adrenomimetics); Isadrin is a β-adrenergic agonists.

49.

A  man  died  from  an  acute  infectious disease accompanied by fever, jaundice,    haemorrhagic   rash    on    the    skin and  mucous   membranes  as  well  as  by acute renal insufficiency. Histological examination of  renal  tissue  (stained by Romanovsky-Giemsa method) revealed some   convoluted  bacteria  looking   like C und S letters.  What bacteria were revealed?

Explanation

krushkrok No25 (2011)        

Three genera of spirochetes cause human infection:

·        Treponema: causes syphilis and the nonveneral treponematoses. Morphology – thin, tight spirals

·        Borrelia: causes lyme disease and relapsing fever. Morphology – large and loosely coiled

·        Leptospira: causes leptospirosis. Morphology – thin, tight spirals

Leptospira is tightly coiled, fine spirochetes that are not stained with dyes but are seen by darkfield microscopy. Leptospira interrogans is the cause of leptospirosis. Human infection results when leptospira is ingested or pass through mucus membranes or skin. They circulate in the blood and multiply in various organs, producing fever and dysfunction of the liver (jaundice), kidney (uremia), lungs (hemorrhage) and CNS (aseptic meningitis). Leptospira C and S letters.

50.

A   12-year-old   adolescent  suffering from bronchial  asthma has a severe attack of asthma:  he presents with marked expiratory  dyspnea,  skin pallor.  What  type of alveolar ventilation disorder is observed?

Explanation

image Obstructive respiratory disease is the abnormal respiratory condition characterized by difficulty in expiration. E.g asthma,chronic bronchitis, emphysema, cystic fibrosis. Restrictive respiratory disease is the abnormal respiratory condition characterized by difficulty in inspiration. E.g poliomyelitis,myasthenia gravis, paralysis of diaphragm, spiral cord diseases, pleural effusion, fibrosis. (lung fibrosis-pneumofibrosis)
51.

A  46-year-old  patient suffering  from the diffuse toxic goiter underwent resection   of   the    thyroid    gland.   After    the surgery the patient presents with appetite loss, dyspepsia,  increased neuromuscular excitement. The body weight remained unchanged. Body  temperature is normal. Which of the following has caused such a condition in this patient?

 

Explanation

       One of the most common complications of thyroidectomy (resection of thyroid gland) is hypoparathyroidism because the parathyroid gland lying behind the thyroid gland capsule can be accidentally removed during the surgery by unskilled surgeons. Accidental removal of the parathyroid gland results in hypoparathyroidism.

52.

A patient who had myocardial infarction was administered 75 mg of acetylsalicinic acid a day. What is the purpose of this administration?

Explanation

Acetylsalicyclic acid (Aspirin) is an NSAID. Cycloxygenase, the enzyme which converts arachidonic acid into the endoperoxide precursors of prostaglandin, has at least two different  isoforms: COX-1 & COX-2. COX-1 is primarily expressed in non-inflammatory cells whereas COX-2 is expressed in activated lymphocytes, polymorphonuclear cells and other inflammatory cells. Acetylsalicyclic acid and the older non-selective NSAIDs inhibit both cyclooxygenase isoforms & thereby decrease prostaglandin & thromboxane synthesis (disaggregating effect) throughout the body.

53. Medical examination at the military registration and enlistment office revealed   that  a  15-year-old  boy  was  high, with eunuchoid body proportions, gynecomastia,  female   pattern  of  pubic hair distribution. The boy had also fat deposits  on the  thighs,  no facial hair,  high voice, subnormal intelligence quotient. Which karyotype corresponds with this disease?

Explanation

krushkrok No70 (2007)

Barr body is an inactive X-chromosome. So a boy (XY) with an inactive X-chromosome must have an additional X-chromosome – XXY (Klinefelter’s syndrome). Causes :

* nondisjunction (maternal and paternal nondisjunction in meiosis I)

* Mosaicism: with the karyotype being 46, XY/47, XXY

Manifestations: gynecomastia, female pattern of pubic hair distribution, no facial hair, high voice.

54.

To  prevent  the  transplant  rejection after   organ   transplantation  it  is  required   to  administer  hormonotherapy  for the purpose of immunosuppression. What hormones are used for this purpose?

Explanation

Glucocorticoids have immunosuppressive effects, anti-inflammatory effects, anti-shock, anti-allergic and anti-toxic effects. Immunosuppressive effects: glucocorticoids inhibit some of the mechanisms involved in cell-mediated immunologic functions, especially those dependent on lymphocytes. These agents are actively lymphotoxic and are important in the treatment of hematologic cancers. The drugs do not interfere with the development of normal acquired immunity but delay rejection reactions in patients with organ transplants. This immunosuppressive effect makes the patient susceptible to other infectious diseases (e.g. chronic tonsillitis).

55.

A 53-year-old  female  patient was diagnosed  with liver rupture resulting  from a  blunt   abdominal  injury.  The  escaped blood  will be  assembled   in  the  following anatomic  formation:

Explanation

krushkrok N013 (2012)

From the bladder, the peritoneum passes onto the uterus to form the vesico-uterine pouch; its floor neighbors the cervix. Posteriorly, the peritoneum covers both intestinal surface and supravaginal part of cervix reaching the posterior surface of vagina. Passing onto the rectum, the peritoneum forms the rectouterine pouch (pouch of douglas). It is the deepest intraperitoneal space in both the upright and the supine position – blood, pus and other free fluids in the peritoneal cavity pool in the pouch because of its dependent location.

56.

A  patient complains  about  edemata of  legs,  skin  cyanosis,   small  ulcers   on one  side  of  the  lateral  condyle.  Examination  revealed  a swelling, enlarged veins, formation of nodes.  The  pathological process has started in the following vein:

Explanation

krushkrok No56 (2009)

The superficial veins of the lower limbs give rise to the great and small saphenous veins (vena saphena magna and parva respectively). They arise from the dorsal and plantar venous networks of foot. The small saphenous vein (vena saphena parva) arises at the lateral aspect of foot. The vein rounds the lateral malleolus and ascends along the posterior surface of leg in between the heads of the gastrocnemius muscle. At the popliteal fossa, the muscle pierces the fascia and joins the popliteal vein.

Great saphenous vein (vena saphena magna) arises from the medial portion of the dorsal venous network of foot and ascends along the medial aspect of the leg and thigh.

57.

A 1,5-year-old child presents with both mental  and  physical  lag, decolorizing  of skin and  hair,  decrease in catecholamine concentration in blood. When a few drops of 5% solution  of trichloroacetic iron had been  added  to the  child’s urine  it turned olive green. Such alteration are typical for the following pathology of the amino acid metabolism:

Explanation

image
58.

Autopsy of a 73-year-old man who had been suffering from the coronary heart disease along  with cardiac  insufficiency for a long time revealed:  nutmeg  liver, brown induration of  lungs,  cyanotic  induration of kidneys  and  spleen.  What  kind  of circulation  disorder was the  cause  of such effects?

Explanation

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In general, these are signs of both right-sided cardiac insufficiency (nutmeg liver – venous congestion) and left-sided cardiac insufficiency (brown induration of lungs – venous congestion). It is Chronic because the patient has been suffering for a long time. In venous or passive hyperemia or congestion, morphologically, the sectioned surface of lungs is dark brown and the process is named brown induration of the lungs. Spleen – cyanotic induration of the spleen; liver – nutmeg liver.

     Acute heart failure refers to sudden and rapid onset of signs and symptoms of abnormal heart functions. Chronic heart failure is characterized by the symptoms that appear slowly over a period of time and become worst gradually.

The main symptoms of right-sided heart failure are fluid accumulation and swelling (edema) in the feet, ankles, legs, liver and abdomen. Left-sided heart failure leads to fluid accumulation in the lungs, which causes shortness of breath. At first, shortness of breath occurs only during exertion, but as heart failure progresses, it occurs with less and less exertion and eventually occurs even at rest. Moist and dry rales are heard over the lungs.

59.

A patient suffering from chronic hyperacidic    gastritis   takes    an   antacid drug  for heartburn elimination. After  its ingestion the patient feels better but at the same time he has a sensation  of stomach swelling. Which of the following drugs might be the cause of such side effect?

Explanation

        Antacids are weak bases that react with gastric acid to form water and a salt to diminish gastric acidity. Because pepsin is inactive at a pH greater than 4, antacids also reduce pepsin activity. They can be:

·        CO2 forming: sodium hydrocarbonate (or carbonate); calcium carbonate

·        Non-forming CO2: magnesium hydroxide, aluminum hydroxide

Uses: hyperacid gastritis, gastric and duodenal ulcers; poisoning with acids.

Adverse effects: in addition to the potential for systemic alkalosis, sodium hydrocarbonate liberates CO2 causing belching and flatulence (sensation of stomach swelling); aluminum hydroxide tends to cause constipation, whereas magnesium hydroxide tends to produce diarrhea.

60.

Continuous use of a certain  drug may cause  osteoporosis, erosions  of  stomach mucosa,  hypokaliemia, retention of sodium and water  in the organism,  decreased concentration of  corticotropin  in  blood. What drug is it?

Explanation

Osteoporosis is a common adverse effect of long-term corticosteroid therapy, due to the ability of glucocorticoids (prednisolone) to suppress intestinal Ca2+ absorption, inhibit bone formation and decrease sex hormone synthesis. Other adverse effects include peptic ulcer (erosions of stomach mucosa), hypokalemia, emotional disturbances and the classic cushing-like syndrome (i.e. redistribution of body fat, puffy face, increased body hair growth, acne, insomnia and increased appetite) are observed when excess corticosteroids are present. Excess corticosteroid results in decreased corticotrophin (adrenocorticotropic hormone) through the negative feedback mechanism.

61.

A patient has been  given high doses of hydrocortisone for a long time. This caused   atrophy  of  one   of  the   adrenal cortex zones. Which zone is it?

Explanation

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The adrenal gland (suprarenal gland) has a secretory parenchymal tissue organized into cortical and medullary regions. Adrenal cortex (derived from mesoderm; steroid-secreting portion) and medulla (derived from neural crest; catecholamine-secreting portion). The adrenal cortex is divided into 3 zones on the basis of arrangement of its cells:

* Zona glomerulosa (15%): arranged in closely packed ovoid clusters; secretes aldosterone.

* Zona fasciculata (80%): large and polyhedral; arranged in long straight cords; secretes cortisol.

* Zona reticularis (5-7%): cells are arranged in anastomosing cords separated by fenestrated capillaries; secretes androgens.

Hydrocortisone is a glucocorticoid (cortisol) and an intake of hydrocortisone will decrease endogenous production of cortisol from zona fasciculata of adrenal cortex leading to its atrophy.

62. A  63-year-old   patient with  collapse presentations was delivered to the emergency  hospital.  A physician  has chosen noradrenalin against hypotension. What is its mechanism of action?

Explanation

image     

Because norepinephrine is the neuromediator of adrenergic nerves, it should theoretically stimulate all types of adrenergic receptors. In practice, when the drug is given in therapeutic doses to humans, the α-adrenergic receptor is most affected. Norepinephrine causes a rise in peripheral resistance due to intense vasoconstriction of most vascular beds, including the kidney (α1 effect). Both systolic and diastolic blood pressures increase. α1 receptors are present on the postsynaptic membrane of the effector organs and mediate constriction of smooth muscle. NB: norepinephrine (noradrenaline) causes greater vasoconstriction than epinephrine, because it does not induce compensatory vasodilation via β2 receptors on blood vessels supplying skeletal muscles.

63.

The greater amount of nitrogen is excreted from  the  organism  in  form  of urea. Inhibition of urea synthesis and accumulation of  ammonia in  blood  and tissues are induced  by the decreased activity of the following liver enzyme:

Explanation

image       

Urea is the major disposal form of amino groups derived from amino acids and account for about 90% of the nitrogen-containing components of urine. Formation of carbomoyl phosphate by carbomoyl phosphate synthetase I is driven by cleavage of two molecules of ATP. Ammonia is incorporated into carbamoyl phosphate. Ultimately, the nitrogen atom derived from this ammonia becomes one of the nitrogens of urea. NB: carbamoyl phosphate synthetase II participates in the biosynthesis of pyrimidines. However, when the function of carbomoyl phosphate synthetase I is compromised, blood ammonia levels rise and urea synthesis is disturbed.

64.

A patient suffering  from  syphilis has been  treated with  bismuth  preparations. As  a result  of it some  grey spots  turned up on the  mucous  membrane of the  oral cavity; nephropathy symptoms  were  also present. What  drug  should  be  used  for treatment of bismuth intoxication?

Explanation

Dimercaprol (unithiol, British anti-lewisite) is used to chelate mercury, bismuth, arsenic and in combination with edentate calcium disodium to treat lead intoxication. It contains two sulfuhydryl (SH-) groups and forms two bonds with metal ions. Administered intramuscularly.

Mannitol – osmotic diuretic; Nalorphine hydrochloride – antidote, blocks opoid receptors and replace opoids from binding with them. Metamizole: analgesic, non-opoid drug. Calcium chloride – Calcium preparation, coagulant with systemic action.

65.

ECG  of a patient shows such alterations: P -wave is normal,  P − Q-interval is short,  ventricular QRST   complex  is wide, R-wave  is double-peak or two-phase. What form of arrhythmia is it?

Explanation

krushkrok No65 (2009) Patients with a history of palpitations and a pre-excited ECG have a syndrome known as Wolff-Parkinson-White (WPW) syndrome. Accessory fibers are most commonly situated on the left but may occur anywhere around the atrioventricular (AV) groove. The most common accessory pathways, known as kent bundles, are in the free wall or septum. Mahaim fibers are atrio-fascicular or nodo-fascicular fibers entering the ventricular myocardium in the region of the right bundle branch. If the accessory pathway conducts from the atrium to the ventricle during sinus rhythm, the electrical impulse can conduct quickly over this abnormal connection to depolarize part of the ventricles abnormally (pre-excitation). A pre-excited ECG is characterized by a short PQ interval and a wide QRS complex that begins as a slurred part known as the δ wave (delta wave).
66.

In a histological specimen parenchyma of an organ is represented by lymphoid tissue that forms lymph nodes; the latter are arranged in a diffuse manner and enclose a central artery. What anatomic  formation has such morphological structure?

Explanation

         The spleen is about the size of a clenched fist and is the largest lymphatic organ. It is located in the upper left quadrant of the abdominal cavity and has a rich blood supply. Most of the spleen consists of splenic pulp. Splenic pulp is divided into two regions: white and red pulp. White pulp consists of a thick accumulation of lymphocytes surrounding a central artery. Lymphocytes that aggregate around the central artery constitute the periarterial lymphatic sheath (PALS). The red pulp contains large numbers of RBCs that it filters and degrades.

67. Examination of a patient with frequent haemorrhages from the internal organs and mucous  membranes revealed  proline and  lysine within the  collagen  fibers. Disorder  of their hydroxylation is caused by lack of the following vitamin:

Explanation

Vitamin C (ascorbic acid): found in fruits and vegetables; an antioxidant; also facilitates iron absorption by reducing it to Fe2+ state. It is necessary for hydroxylation of proline and lysine in collagen synthesis; necessary for dopamine β-hydroxylase, which converts dopamine to norepinephrine. Deficiency leads to: scurvy – swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, “corkscrew” hair; Weakened immune response.

Type III collagen is found in blood vessels; Type IV collagen is found in basement membrane. Deficiency in Vitamin C disrupts the second stage of collagen synthesis in fibroblasts (hydroxylation of collagen) which results in petechiae, bruising, hemarthrosis.

Vitamin B2 (riboflavin) deficiency – growth retardation, glossitis, conjunctivitis

Vitamin B1 (thiamine) deficiency – Beri-Beri (polyneuritis)

Vitamin A (retinol) deficiency – Night blindness

Vitamin B9 (folic acid) deficiency – macrocytic megaloblastic anemia

68.

During  a prophylactic medical examination   a  7-year-old   boy  was  diagnosed with  daltonism.   His  parents are  healthy and have normal colour vision, but his grandfather on his mother’s side has the same abnormality. What is the type of the abnormality inheritance?

Explanation

image

Autosomal dominant: often due to defects in structural genes. Many generations, both male and female are affected. Found in every generation; no generation is left out (skipped). Parent – child in every generation.

Autosomal recessive is usually seen in some generations (other generations are skipped).

It is sex linked, if only males or only females(X-linked) are affected.

Parents are healthy (i.e. a generation was left out) – recessive

Grandfather – Boy (sex linked)

69.

In   a   healthy   adult   speed   of   the excitement conduction through the  atrioventricular node is 0,02-0,05 m/sec. Atrioventricular delay enables:

Explanation

The atrial conductive system is organized so that the cardiac impulse does not travel from the atria into the ventricles too rapidly; this delay allows time for the atria to fully contract and empty their blood into the ventricles before ventricular contraction begins. It is primarily the AV node and its adjacent conductive fibers that delay this transmission into the ventricles.
70.

A  histological  specimen  of a kidney shows a part of the distal tubule going between the  afferent and  efferent arteriole. The cells building the tubule wall have dense  nuclei;  basal  membrane is absent. Such structural formation is called:

Explanation

imagekrushkrok No140 (2012)

         Juxtaglomerular apparatus is formed by 3 different structures:

·        Macula densa: is the end portion of thick ascending segment as it opens into the distal convoluted tubule. It is situated between the afferent and efferent arterioles of the same nephron. It is very close to afferent arteriole. Macula densa is formed by tightly packed cuboidal epithelial cells.

·        Mesangial cells: are situated in the triangular region bound by afferent arteriole, efferent arteriole and macula densa.

·        Juxtaglomerular cells: are specialized smooth muscle cells situated in the wall of afferent arteriole just before it enters the Bowman’s capsule.

71. Stimulation of an excitable  cell by the electric current has led to the depolarization  of its  membrane. The  depolarization has been  caused  mainly by the  following ions penetrating into  the  cell through its membrane:

Explanation

Nerve signals are transmitted by action potential (AP), which are rapid changes in the membrane potential that spread rapidly along the nerve fiber membrane. During the depolarization stage of an AP, the membrane suddenly becomes permeable to sodium ion (Na+), allowing tremendous number of positively charged Na+ to diffuse to the interior of the axon. A major function of voltage-gated calcium ion (Ca2+) channels is to contribute to the  depolarizing phase on the action potential in some cells. Although the gating of calcium channel is slow (slow channels), in contrast to the fast sodium channels. Therefore, sodium channels play a key role in initiation and conduction of action potentials.

72.

Products of some  proteins hydrolysis and   modification    are   the   biologically active substances  called hormones. Lipotropin,    corticotropin,    melanotropin and endorphins are synthesized  in the hypophysis  of the following protein:

Explanation

When adrenocorticotropic hormone (ACTH) is secreted by the anterior pituitary gland, several other hormones that have similar chemical structures are secreted simultaneously. The reason for this is that the gene that is transcribed to form the RNA molecule that causes ACTH synthesis initially causes the formation of a considerably larger protein, a preprohormone called proopiomelanocortin (POMC), which is the precursor of ACTH (corticotrophin) and several other peptides, including melanocyte-stimulating hormone (melanotropin), β-lipotropin, β-endorphin and a few others.

73.

In patients with the biliary tract obstruction the blood coagulation is inhibited;  the patients have frequent haemorrhages caused  by  the  subnormal assimilation  of the following vitamin:

Explanation

Vitamin K is a fat soluble vitamin together with Vitamin A, D and E i.e. bile acid and fat emulsification is essential for their absorption in the small intestine. in biliary tract obstruction, there is decreased bile acid, which leads to decreased fat emulsification and absorption, therefore resulting in decreased fat soluble vitamins (Vitamin A, D, E, K).

Vitamin K is essential for the formation of various clotting factors in the liver, namely clotting factor II, VII, IX and X; Protein C and S.

Factor II – Prothrombin

Factor VII – Stable factor

Factor IX – Christmas factor

Factor X – Stuart-Prower factor

These factors undergo vitamin K-dependent post-translational modification, whereby a number of their glutamic acid residues are carboxylated to form ɣ-carboxyglutamic acid residues. The ɣ-carboxyglutamyl residues bind calcium ions which are essential for interaction between the coagulation factors and platelet membranes. This oral anticoagulants block epoxide reductase and creation of active form of vitamin K resulting in disturbances in prothrombin and proconvertin synthesis in liver.

Prothrombin time (PT) evaluates the extrinsic coagulation system down to the formation of the fibrin clot. Factors that are evaluated include factor VII, X, V, II, and I. PT is increased when a factor level is 30% - 40% of normal. Vitamin K-dependent factors include factor II, VII, IX and X; protein C and S. vitamin K is activated in the liver by epoxide reductase. Activated vitamin K ɣ-carboxylates each of the vitamin K-dependent factors. Carboxylated factors are now able to bind calcium, which are essential for interaction between the coagulation factors and platelet membranes.

74.

A  48-year-old   patient was  admitted to the hospital with complaints about weakness, irritability, sleep disturbance. Objectively:  skin and scleras are of yellow colour.  In blood:  increased  concentration of total bilirubin  with prevailing direct bilirubin. The feces are acholic. The urine is dark  (contains  bile pigments).  What  type of jaundice  is it?

Explanation

image 

Indirect; Hemolytic; Prehepatic

Mixed; Parenchymal; Hepatic

Direct; Obstructive; Mechanic; Posthepatic

Stercobilin (faeces)

        ↑↑↑

Decreases (pale faces)

Absent (clay coloured faeces)

Type of bilirubin in blood

Unconjugated

Conjugated and Unconjugated

Conjugated

Obturation (obstruction, to close) of bile duct – it can be:

* Intrahepatic – blockage of intrahepatic bile ducts

* Extrahepatic – blockage of common bile duct (ductus choledochus).

Findings:

* malabsorption: bile salts do not enter the Small Intestine; no emulsification of fat.

*light coloured stool: due to lack of urobilin (which leads to lack of stercobilin).

*Jaundice (posthepatic, mechanic, obstructive): increased conjugated Bilirubin.

* Steatorrhea

The findings are specific for obstruction of bile duct and bile acid deficiency.

75.

A bacteriological laboratory has received  smears  from  the  sputum   of  a  patient with a chronic pulmonary disease. Microscopical  examination of the smears stained   by  the  Ziehl-Neelsen technique revealed  red bacilli. What property of the tuberculosis bacillus has shown itself?

Explanation

image

Mycobacteria are aerobic, acid fast bacilli (rods). They are neither gram +ve nor  gram -ve i.e. they are stained poorly by the dyes used in gram stain. They are virtually the only bacteria that are acid-fast (one exception is Nocardia asteroids, the major cause of Nocardiosis, which is also acid-fast). The term  “acid-fast” refers to an organism’s ability to retain the carbolfuchsin stain despite subsequent treatment with an ethanol-hydrochloric acid mixture. The high lipid content (approx. 60%) of their cell wall makes Mycobacteria acid-fast.The major pathogens are Mycobacterium tuberculosis, the cause of tuberculosis and Myobacterium lepra, the cause of leprosy. M. tuberculosis grows slowly. Its cell wall contains long chain (C78-C90) fatty acids called mycolic acids, which contribute to the organism’s acid-fastness. Ziehl-Neelsen stain is also known as acid-fast stain.

76. Microscopical examination of an enlarged cervical lymph node revealed blurring  of its structure, absence  of lymphoid  follicles; all the  microscopic  fields showed cells with roundish nuclei and thin limbus of basophil cytoplasm. It is known from the clinical data that other groups  of lymph  nodes  are  also enlarged as well as spleen  and  liver. What  disease might be suspected?

Explanation

        Lymphoid leukosis is a type of malignant neoplasm characterized by the proliferation of cells native to the lymphoid tissues; that is - lymphocytes, histiocytes and their precursors and derivatives. It is characterized by an enlarged liver due to infiltration of cancerous lymphoid cells. In addition, other abdominal organs are also affected.

77.

Two weeks after lacunar tonsillitis a 20- year-old  man  started complaining  about general weakness, lower eyelid edemata. After  examination the patient was diagnosed with acute glomerulonephritis. What are the most likely pathological changes in the urine formula?

Explanation

Presence of excess protein (proteinuria) particularly albumin (albuminuria) in urine indicates renal diseases. Urinary excretion of albumin in a normal healthy adult is about 30mg/day. It exceeds this level in glomerulonephritis. It also increases in fever and severe exercise.

78.

A 38-year-old  patient came to a traumatology   centre    and    complained about  an injury of his right hand. Objectively: the  patient has a cut wound  in the region of the thenar eminence on the right hand; distal phalanx  of the I finger cannot be flexed. What muscle was injured?

Explanation

          The muscles of the hand are divided into 3 groups: muscles of the thumb (thenar muscles); muscle of the fifth digit (hypothenar eminence) and central palmar muscles. Flexor pollicis longus (long flexor muscle of thumb) resides laterally in the deep layer. It flexes the thumb.  Its tendon passes under the flexor retinaculum onto the palm and inserts into the base of the distal phalanx of the thumb.

Flexor pollicis brevis (short flexor muscle of thumb) and abductor pollicis brevis (short abductor muscle of thumb) attaches to the base of the proximal phalanx of the thumb. Opponens pollicis (opposer muscle of thumb) attaches to the first metacarpal bone. It is the deepest of the thenar muscles. Abductor pollicis (abductor muscle of thumb) inserts into the base of the proximal phalanx of the thumb.

NB: first (I) finger – Thumb

79.

Lung   ventilation   in   a   person    is increased   as  a  result  of  physical  activity. Which  of the  following  indices  of the external  respiration is much  higher  than in a state of rest?

 

Explanation

        During physical activity all lung volumes tend to increase to meet up with the increased demand. Therefore, the whole respiratory volume is increased – inspiratory reserve volume, expiratory reserve volume, tidal volume; vital capacity includes inspiratory reserve volume, tidal volume and expiratory reserve volume. Total lung capacity is the volume of air present in lungs after a deep (maximal) inspiration.

80. As  a  result   of  continuous  starvation the glomerular filtration  rate has increased   by  20%.  The   most   probable cause of the glomerular filtration  alteration under  the mentioned conditions is:

Explanation

       Starvation decreases protein synthesis because the substrates are not readily available. Decrease in protein synthesis decreases oncotic pressure and thereby increasing glomerular filtration. Net filtration pressure is the balance between hydrostatic pressure (glomerular capillary pressure) and oncotic pressure.

Net filtration pressure = Hydrostatic pressure – Oncotic pressure

Therefore, a decrease in oncotic pressure increases the filtration rate according to the degree of starvation which decreases protein synthesis.

81. After  transfusion of 200 ml of blood a patient presented with body temperature rise up to 37, 9oC . Which  of the  following substances  is the  most  likely cause  of temperature rise?

Explanation

       The transfused blood might contain pyrogens or its an incompatible blood that activates the immune system. Pyrogenic cytokines, principally IL-1; IL-6 and TNF-α are released into the bloodstream for transport to the hypothalamus, where they exert their action. These cytokines induce prostaglandin E2 (PGE2), which is a metabolite of arachidonic acid. It is hypothesized that when IL- 1β interacts with the endothelial cells of the blood-brain barrier in the capillaries of the organum vasculosum laminae terminalis (OVLT), which is in the third ventricle above the optic chiasm, PGE2 is released into the hypothalamus. At this point PGE2 binds to receptors in the hypothalamus to induce increase in the thermostatic set point through the second messenger cAMP. In response to the increase in its thermostatic set point, the hypothalamus initiates shivering and vasoconstriction that raise the body’s core temperature to the new set point and fever is established.

82.

A man who is riding the carousel presents with increased  heart  rate, sweating, nausea.  This  condition is caused  primarily by the stimulation of the following receptors:

 

Explanation

       The receptor areas of the vestibular labyrinth are represented with the following structures:

·        Macula of Utricle

·        Macula of Saccule

·        Ampullary crests

The first two detect linear motion, while the ampullary crest detect angular motion. The vestibulocochlear nerve supply these receptors. Both maculae consist of the sensory hair cells covered with jelly-like susbstance. The substance contains the crystals of calcium carbonate called otoliths (vestibular otolith). The utricle and saccule detect linear movement, also contributing to balance. The ampullary crests reside within each membranous ampulla. They also comprise the sensory hair cells covered with the same jelly-like substance called the ampullary cupula. The ampullae is the sensory organ in the semicircular canal that sense angular (rotational) acceleration of the head, thereby regulating balance. NB: carousel is a revolving belt.

83.

A worker  of a cattle  farm fell acutely ill and then died from the progressing intoxication. Autopsy revealed  enlarged, hyposthenic spleen  of dark-cherry colour when  dissected;  excessive  pulp  scraping. At the base and fornix of brain pia maters are  edematous, soaked  with blood,  dark- red  (\\\"scarlet hat\\\").   Microscopic   examination revealed serous haemorrhagic inflammation  of  brain  tissues  and  tunics along  with destruction of small vessel walls. What is the most likely diagnosis?

Explanation

There are two medically important Bacillus species: Bacillus anthracis and Bacillus cereus. Bacillus anthracis causes anthrax. Human disease occurs in 3 main forms: cutaneous, pulmonary (inhalation) and gastrointestinal. Humans are most often infected cutaneously at the time of trauma to the skin, which allows the spores on animal products such as hides, bristles and wool to enter. Spores can also be inhaled or when contaminated meat is ingested. After being inhaled, the organism moves rapidly to the mediastinal lymph nodes and causes hemorrhagic mediastinitis. Pathogenesis is based on the production of two exotoxins  (Anthrax toxin) – edema factor and lethal factor. Hemorrhagic mediastinitis, septic shock hemorrhagic meningitis and death are severe life-threatening complications. In fatal cases, the organism may affect the spleen, liver, intestines, kidneys, adrenal glands and meninges.

Live spore vaccine (STI) is used for vaccination against anthrax. STI live vaccine
84.

A   49-year-old   patient  consulted   a doctor about increased fatigability and dyspnea   provoked  by  physical   activity. ECG   results:  heart   rate   -  50/min,  P Q- interval    is   prolonged,   QRS-    complex is  unchanged,  the   number   of  P -waves exceeds  the  number  of QRS-complexes. What type of arrhythmia is it?

Explanation

Atrioventricular (AV) block is the heart block in which the impulses are not transmitted from atria to ventricles (through AV node) because of defective conductive system. AV block can be 1st degree, 2nd degree (Mobitz I and II) and 3rd degree heart block. In complete or 3rd degree heart block, the impulses produced by the sinoatrial (SA) node cannot get to the ventricles. Therefore, atrial P waves and ventricular complexes (QRS) are recorded independently of each other; the number of ventricular complexes is usually much smaller than the number of atrial (P) waves (i.e. the number of P waves exceeds the number of QRS complexes). The heart rate in persistent complete heart block may be sufficiently high (40 – 50 beats/min) but the patient may be unaware of the disease for a long time.

Sinoatrial (SA) block is the failure of impulse transmission from SA node to AV node. It is also called sinus block. It is characterized by periodic missing of the heart beat and pulse beat. The ECG shows periodic missing of the heart complex (neither P-wave nor the QRST complex are recorded); the length of diastole doubles.

85.

A  patient  suffering   from   coronary artery    disease    had    taken    a    certain drug   many   times   a   day   in   order   to arrest   stenocardia  attacks.   Overdose  of this drug finally caused intoxication. Objectively: cyanotic skin and mucous membranes, dramatic fall in the  arterial pressure, tachycardia, respiration inhibition. Blood  has increased concentration of methemoglobin. The drug the patient had taken  relates to the following group:

Explanation

The most common drug used in treating stenocardia is organic nitrates (nitroglycerine). High doses of organic nitrates can cause postural hypotension, facial flushing, tachycardia and headache. Overdose can increase nitrates concentration in blood leading to the formation of methemoglobin with a decreased ability to bind O2. This results in shortness of breath (respiratory inhibition), cyanosis, mental status changes, fatigue etc.

86.

A  patient  with  android-type  obesity had been suffering from arterial hypertension, hyperglycemia, glycosuria for a long time and died from the cerebral haemorrhage. Pathologic  examination revealed  pituitary basophil  adenoma, adrenal cortex  hyperplasia. What  is the most likely diagnosis?

Explanation

krushkrok No159 (2012)

Cushing Syndrome: Etiology

 *INCREASE Cortisol due to a variety of causes (Glucocorticoids).

*Exogenous corticosteroids:  result in DECREASE ACTH (MCC).

*Primary adrenal adenoma, hyperplasia or carcinoma (Cushing’s Syndrome).

 *ACTH-secreting pituitary adenoma (Cushing Disease).

Findings: Hypertension, Weight Gain, Moon Facies, Truncal Obesity, Buffalo Hump, Skin Changes (thinning striae), Osteoporosis, Hyperglycemia (Insulin resistance), Amenorrhea, Immunosuppression.

87.

A middle-aged man went to a foreign country because he had been offered a job there.  However he had been unemployed for  quite   a  long  time.  What   endocrine glands were exhausted most of all in this man?

Explanation

Due to the fact that he has been unemployed for a long time, the man has been stressed. Unemployment can lead to psycho-emotional stress. The main stress organ in the body is the adrenal gland producing stress hormones (cortisol, catecholamines). Therefore, this gland must have been exhausted, if the man has stayed unemployed for a long time.

88. A   girl   has   been   diagnosed    with adrenogenital syndrome (pseudohermaphroditism).    This    pathology    is   caused    by hypersecretion of  the  following  adrenal hormone:

Explanation

Adrenogenital syndrome results from the hereditary stipulated blockade of cortisol synthesis and amplified formation of androgens from general intermediate products.

89. A woman  delivered  a dead  child with multiple  developmental defects.  What protozoan disease  might have caused  the intrauterine death?

Explanation

ToRCHeS infections: Toxoplasma gondii; Rubella; Cytomegalovirus; HIV; Herpes simplex virus-2; Syphilis. These are microbes that may pass from mother to fetus. Transmission is transplacental in most cases or via delivery. Toxoplasma gondii causes toxoplasmosis. It is transmitted from cat faeces or ingestion of undercooked meat. Congenital infection of the fetus occurs only when the mother is infected during pregnancy. Congenital infection can result in abortion, stillbirth or neonatal disease with encephalitis, chorioretinitis and hepatosplenomegaly.

90.

A patient has a massive haemorrhage caused    by   damage    of   the   dorsal    lingual  artery   by  cancer  of  tongue   back. What vessel should be ligated for the haemorrhage arrest?

Explanation

krushkrok No97 (2007)

The lingual artery arises at the level of posterior horn of the hyoid bone from the external carotid artery. The artery occupies the lingual triangle (of Pirogov) immediately below the hyoglossus muscle. It gives the dorsal lingual branches, deep lingual artery and sublingual artery.

91.

A 12-year-old  teenager has significantly put off weight within 3 months; glucose  concentration rose  up  to  50 millimole. He fell into a coma. What  is the main mechanism  of its development?

Explanation

        Hyperosmolar coma is clinically defined by the presence of relative insulin deficiency and hyperglycemia (high glucose concentration), usually higher than 33.3mmol/L with associated elevated serum osmolality (>300mosm/kg), dehydration and stupor, progressing to coma if uncorrected, without the presence of ketosis or acidosis.

Hypoglycemic coma → ↓ glucose concentration

Ketonemic coma → ↑ ketone bodies

Lactacidemic coma → ↑ lactic acid

92.

As  a  result  of  increased   permeability     of    the     erythrocyte    membrane in  a  patient with  microspherocytic anaemia  (Minkowsky-Shauffard disease) cells receive sodium ions and water. Erythrocytes  take   form   of  spherocytes and  can  be  easily  broken  down.  What is the  leading  mechanism  of erythrocyte damage  in this case?

 

Explanation

Hemolytic anemia: according to the mechanisms of the development, they are divided into 3 groups namely:

·        Erythrocytic membrane structure (membranopathy)

·        Erythrocytic enzyme activity (enzymopathy)

·        Structure or rate of hemoglobin synthesis (hemoglobinopathy)

    Membranopathies are characterized by disorders of protein or lipid components of the erythrocytic membrane structure. Membranopathies caused by the disorders of protein structure includes:

o   Hereditary spherocytosis (Minkowsky-shauffard disease)

o   Hereditary elliptocytosis (ovalocytosis)

o   Hereditary pyropoikilocytosis

o   Hereditary and acquired stomatocytosis

     In addition, the membrane defect leads to a loss of both potassium and water, which produces cellular dehydration and results in erythrocyte damage (electrolytic osmotic).

93. A   histological    specimen    shows   a blood  vessel. Its  inner  coat  is composed by endothelium, subendothelium and internal  elastic  membrane.  The   middle coat  is enriched with  smooth  myocytes. Such   morphological  characteristics  are  typical for the following vessel:

Explanation

krushkrok No67a (2011)

The tunics of veins are not as distinct or well defined as the tunics of arteries. Veins are divided into 3 types:

* Small veins/venules: postcapillary and muscular venules

* Medium veins

* Large veins

Arteries:

·        Large or elastic arteries

·        Medium or muscular arteries

·        Small arteries and arterioles

Muscular venules are distinguished from postcapillary venules by the presence of a tunica media. Postcapillary venules possess an endothelial lining with its basal lamina and pericytes. Postcapillary venules have no true tunica media.

·        Tunica intima: consists of endothelium with its basal lamina

·        Tunica media: smooth muscle cells

·        Tunica adventitia: collagen fibers

A vessel without tunica media, also lack muscular tissue. Muscular artery, arteriole and artery of mixed type all have tunica media. Only capillaries and postcapillary venules lack tunica media.

Also a prominent internal elastic membrane helps to distinguish muscular arteries from elastic arteries and muscular venules.

94.

Cooling of the human body in water is much  more  faster  than  in the  air.  What way  of  heat  emission  in  water  is much more effective?

Explanation

Conduction is a way the body eliminates heat by means of direct contact with another object. Heat is transferred down the temperature gradient (i.e. from the object of higher temperature to the object of lower temperature). Conduction requires contact with another object (Key words:  in water).

Heat Radiation is a way the surface of the human body emits heat to the environment in the form of infrared rays. The amount of heat the body radiates to the environment is proportional to the surface of radiation area and to the difference between the mean values of skin and environment temperature. The surface radiation area is the total surface area of body parts that contact the air. Elimination of heat by radiation increases with a decrease in ambient temperature and decreases with its increase. It is possible to reduce elimination of heat by radiation via reduction of the surface of radiation area (“winding oneself into a ball”). Heat radiation does not require a medium for transfer of heat. (Key words: naked or lightly clothed).

Convection is a way the body eliminates heat by means of transferring heat via moving particles of air or water. To dissipate heat by means of convection, body surface shall be airflowed at a temperature that is lower than the temperature of the skin. At that, air layer contacting with the skin warms up, decreases its density, rises and is replaced by cooler, denser air. By increasing the speed of the air flow (wind, ventilation) heat emission increases significantly as well (forced convection). Convection requires convection current; current of gases or liquids (Key words: air over exposed area of skin).

Evaporation is a way the body dissipates heat to the environment by its evaporation via sweat or evaporation of moisture from the skin and respiratory tract mucous membranes of (“wet” heat loss). Evaporation closely related to relative humidity.

 

95.

An  18-year-old  man  was delivered  to the hospital  after a road accident.  Examination  at the traumatological department revealed multiple injuries of soft tissues of face in the region of the medial eye angle. The injuries caused massive haemorrhage. What   arterial  anastomosis  might   have been damaged in this region?

Explanation

krushkrok No68a (2011)        

Common carotid artery branches to give: external carotid artery and internal carotid artery.

External carotid artery → facial artery → angular artery

Internal carotid artery → ophthalmic artery → dorsal nasal artery

Angular artery is the terminal segment of facial artery which branches within the medial angle of the eye. It anastomoses with the branches of the ophthalmic artery (i.e. the dorsal nasal artery). The two big arteries connected are the external carotid artery and the internal carotid artery.

96. After  a surgery  a 36-year-old  woman was given an intravenous injection of concentrated albumin  solution.  This  has induced   intensified   water   movement  in the following direction:

Explanation

Albumin maintains the oncotic pressure in the blood vessels, it does not go out of the blood vessels. Injection of concentrated solution of albumin will increase the oncotic pressure in the blood vessel thereby causing water to move from the interstitial/intercellular space to the blood vessel (i.e. the capillaries).

    In contrast, glucose can pass through the capillaries into the interstitial/intercellular space but it does not readily enter the cell. Therefore, it increases the oncotic pressure in the interstitial space and cause water to move from the intracellular (inside the cell) space to the interstitial/intercellular space.

97.

Autopsy  of   a   man   with   a   malignant    stomach    tumour   who   had   died   from   cancer    intoxication  revealed in the posteroinferior lung fields some dense, grayish-red  irregular foci protruding above the section surface. Microscopic examination  revealed   exudate  containing a large  amount of neutrophils in the lumen and walls of small bronchi and alveoles. Such pulmonary alterations indicate the following disease:

Explanation

      Bronchopneumonia (focal pneumonia) is marked by patchy exudative consolidation of lung parenchyma. Bronchopneumonia often is a complication of other disease (complication of stomach cancer). Initially bronchi are affected. Then, inflammation spreads to parenchyma of lungs with accumulation of exudates in the alveoli. Grossly, the lungs show dispersed, elevated, focal areas of palpable consolidation and suppuration. Histological features consist of acute (neutrophilic) suppurative - purulent or mixed exudates filling airspaces and airways, usually around bronchi and bronchioles.

98. Autopsy   of    a    1,5-year-old    child revealed  haemorrhagic skin rash, moderate hyperaemia and edema  of nasopharyngeal mucous membrane, small haemorrhages in the mucous  membranes and  internal organs;  dramatic  dystrophic alterations in liver and myocardium; acute necrotic nephrosis; massive haemorrhages in  the  adrenal glands.  What  disease  are these alterations the most typical for?

Explanation

Morphologically, meningitis can be: meningococcal nasopharyngitis, meningococcal meningitis, meningococcemia. In meningococcemia, changes on the organs are characterized by generalized damage of microcirculation, skin rash, changes in the joints, vascular membrane of the eyes, adrenal glands and kidneys. Changes in the serous layers of the pericardium are observed. The rash is hemorrhagic, star-like, located mainly on the buttocks, lower extremities, eyelids and scleras. Focal necrosis and hemorrhages or bilateral massive hemorrhages with the development of acute adrenal insufficiency (waterhouse-friderichsen syndrome) are noted in the adrenals. Necrosis of nephrothelium of the tubules (necrotic nephrosis) is observed in the kidneys.

Meningococcal meningitis is characterized by hyperemia of pia mater (extremely plethoric), by the end of the 2nd – 3rd day the exudate becomes thicker, green-yellow, purulent (yellow-green cap). Dull-serous exudates during the first days of the disease.
99. During     examination   of    an    11- month-old infant  a pediatrician revealed osteoectasia of the lower extremities and delayed  mineralization of  cranial  bones. Such pathology is usually provoked by the deficit of the following vitamin:

Explanation

image

Rickets results from insufficiency of vitamin D (calcitriol). Calcitriol is the active form of vitamin D. calcitriol production is dependent on the kidney’s 1-α-hydroxylase which converts 25-OHD3 to 1,25-(OH)2D3 (calcitriol). So in cases of renal lesion, there is lack of 1-α-hydroxylase which leads to a deficiency of calcitriol or impaired synthesis of calcitriol. [Cholecalciferol - Vit D]

Osteoectasia is bowing of the bones, particularly of the legs  (bowed leg).

100.

Examination of  a  patient suffering from  chronic  hepatitis revealed  a significant decrease in the synthesis and secretion of bile acids. What process will be mainly disturbed in the patient’s bowels?

Explanation

The findings are specific for obstruction of bile duct and bile acid deficiency.

Findings:

* malabsorption: bile salts do not enter the Small Intestine; no emulsification of fat.

*light coloured stool: due to lack of urobilin (which leads to lack of stercobilin).

*Jaundice (posthepatic, mechanic, obstructive): increased conjugated Bilirubin.

* Steatorrhea

101. Retrospective diagnostics of bacterial dysentery involved serological  analysis of blood  serum  intended for  determination of Shigella antibody  titre. Which of the following reactions should  be applied  for this purpose?

Explanation

Hemagglutination tests: many viruses clump red blood cells from one species or another (active hemagglutination). This can be inhibited by antibody specifically directed against the virus (hemagglutination inhibition) and can be used to measure the titer of such antibody. Red blood cells (RBCs) also can absorb many antigens and when mixed with matching antibodies, they will clump (this is known as passive hemagglutination, because the Red cells are passive carriers of the antigen).

102. You are studying functioning of a bacteria operon. The operator gene has   been   released  from   the   repressor gene.  Immediately after  this the  following process will start in the cell:

Explanation

Prokaryotic operons contain an operator – a segment of DNA that regulates the activity of the structural genes of the operon. If the operator is not bound by a repressor molecule, RNA polymerase passes over the operator and reaches the protein-coding genes which it transcribes to mRNA. If a repressor molecule is bound to the operator, the polymerase is blocked and does not produce mRNA. As long as the repressor is bound to the operator, no transcription and therefore no proteins are made. However, when an inducer molecule is present, it binds to the repressor, causing the repressor to change shape so that it no longer binds the operator. When this happens, the RNA polymerase can proceed with transcription.

103.

While determining power inputs of a patient’s  organism  it was established that the   respiratory  coefficient   equaled  1,0. This  means  that  in the  cells of the  patient the following substances are mainly oxidized:

 

Explanation

Minute O2 uptake – 1000ml

    Minute CO2 emission – 1000ml

    Respiratory Quotient (RQ) = vCO2 /vO2 = 1000/1000(ml) = 1

   Carbohydrate = 1; Fat = 0.7; Protein = 0.8

104.

During   an  experiment  the   dorsal roots of the spinal cord of an animal have been  cut. What  changes  will be observed in the innervation zone?

Explanation

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There are two types of roots of spinal nerves:

·        Anterior (ventral, motor) root: it arises from the anterolateral sulcus and contains a set of axons of motor neurons located within the anterior columns; the anterior roots number 31 pairs.

·        Posterior (dorsal, sensory) root: it is a set of central processes of sensory pseudounipolar neurons located within the spinal ganglia; the posterior roots also number 31 pairs. Cutting this root will lead to loss of sensory stimulus.

105.

An experimental animal has lost orientative reflexes  as a result  of destruction of certain  brainstem structures. What structures had been destroyed?

Explanation

       Quadritubercular bodies/tectal plate is the dorsal portion of the midbrain comprises 4 colliculi – two superior and two inferior. The nuclei of colliculi are responsible for reflexes associated with sudden sound and visual stimuli (auditory and visual orientative reflexes); they also maintain consciousness. The nuclei give rise to the tectospinal tract. Superior colliculi – visual orientative reflex; Inferior colliculi – auditory orientative reflex.

106. A  patient has  osmotic  pressure of blood plasma at the rate of 350 mOsmol/l (norm  is 300 mOsmol/l).  This will cause hypersecretion of the following hormone:

Explanation

       Antidiuretic hormone (vasopressin) is secreted in response to decrease blood volume and increase plasma osmolarity. It binds to receptors on principal cells of collecting ductules causing increase number of aquaporins and increase water reabsorption which leads to decreased diuresis.

↑oncotic (colloid-osmotic) pressure → ↑vasopressin → ↑H2O reabsorption → Normal osmotic pressure. ↑H2O reabsorption will balance the excess osmotic pressure.

↓vasopressin → ↓H2O reabsorption → polyuria

107.

After  a  sprint  an  untrained person develops muscle hypoxia. This leads to the accumulation of the following metabolite in muscles:

Explanation

Athletes that are exercising intensely for the short periods of time, such as in a sprint race, build up large amounts of lactate in their muscles as the result of anaerobic glycolysis. The “warming down” period of continual movement under aerobic conditions performed by athletes for approximately 15mins after a race increases circulation and removes lactate from the muscles.

Lactate, formed by the action of lactate dehydrogenase (converting pyruvate to lactate) is the final product of anaerobic glycolysis in eukaryotic cells.

Aerobic glycolysis progresses to citric acid cycle from pyruvate. The cycle occurs totally in the mitochondria.

108. Cytoplasm of the myocytes contains a lot of dissolved metabolites resulting from glucose  oxidation.   Name  the  metabolite that turns directly into lactate:

Explanation

Lactate, formed by the action of lactate dehydrogenase (converting pyruvate to lactate) is the final product of anaerobic glycolysis in eukaryotic cells. In organs or cells that are poorly vascularized and/or lack mitochondria, formation of lactate is the major fate of pyruvate as seen in lens, cornea of the eye, kidney medulla, testes, leukocytes and red blood cells.

109.

A young man complains about urination disorder. Examination of the external genitals revealed that the urethra was split and urine  could flow out of this orifice. What anomaly of the external genitals development is it?

Explanation

image

Defects in male genitalia:

Hypospadia: fusion of the urethral folds is incomplete and abnormal openings of the urethra occur along the inferior (undersite) surface of the penis, usually near the glans, along the shaft or near the base of the penis.

Epispadia is a rare abnormality (1/30000 births) in which the urethral meatus is found on the dorsum (superior) surface of the penis.

110.

A   patient  consulted   an   urologist about  pain  during  urination. Analysis  of his urine  taken  in the  daytime  revealed eggs with a characteristic sharp point. It is known  from the anamnesis  that  the patient has recently  returned from Australia. What is the most likely diagnosis?

Explanation

The most important trematodes (flukes) are Schitosoma species (blood flukes). Schistosoma causes Schistosomiasis. Schistosoma mansoni and Schistosoma japonicum affect the GIT, whereas Schistosoma haematobium affects the urinary tract. Schistosoma haematobium’s eggs have a terminal spine (sharp point) and lives in the veins draining the urinary bladder. Schistosoma haematobium is found in Africa and the middle-east. Diagnosis depends on finding the characteristic ova (egg) in faeces or urine.

111.

Colonoscopy   of   a   patient   with dysentery revealed  that the mucous membrane of the large intestine was hyperemic, edematic,  and  its surface  was covered  with grey-and-green layerings. What  morphological form  of  dysenteric colitis is it?

 

Explanation

Morphology of dysenteric colitis has 4 stages: catarrhal colitis; fibrinous colitis; ulcer formation (ulcerative colitis); healing of the wound. During the stage of fibrinous colitis, within the course of 24hours, a fibrinosuppurative exudate first patchily, then diffusely covers the mucosa and produces a dirty grayish pseudomembrane, consisting of necrotic mucosa, neutrophils, fibrin and erythrocytes. Sloughed pseudomembrane, together with blood-tinged mucus, comprises the characteristic dysenteric stool.

112.

Examination of  a  patient 24 hours after  appendectomy revealed  neutrophilic leukocytosis   with  a  regenerative shift. What  is the  most  likely mechanism  of leukocytosis  development?

Explanation

Neutrophilic leukocytosis: increase in neutrophil count. Depending on the proportion between the mature and premature forms of neutrophils, two types of the nuclear shift may be distinguished: to the left, when there is an elevated content of immature forms of neutrophilic granulocytes (myelocytes, metamyelocytes, bands) in the blood; And to the right, when the mature neutrophils with a large number of segments (5 – 6) prevail against a background of younger cells disappearing. The nuclear shift may be subdivided into: regenerative, hyperregenerative, degenerative and regenerative-degenerative shifts.

Regenerative shift develops against a background of mild general leukocytosis, accompanied with elevated content of bands and metamyelocytes (immature forms). This shift results from the reactive leukopoiesis (granulocytopoiesis) activation and is common in suppurative septic processes.

113.

A   35-year-old    patient  complains about  having  severe  rhinitis  and  loss  of sense of smell for a week. Objectively: the nasal cavity contains a lot of mucus covering  the  mucous  membrane and  blocking olfactory  receptors. In what region of the nasal cavity are these receptors located?

Explanation

     Olfactory receptors are situated in olfactory mucus membrane, which is the modified mucus membrane that lines upper part of nostril (superior nasal concha). Olfactory receptor cell is a bipolar neuron. Dendrite of this neuron is short and it has an expanded end called olfactory rod. From the olfactory rod, about 10-12 cilia arise. These cilia project to the surface of olfactory mucus membrane in the upper part of nostril. Mucus secreted by Bowman glands continuously lines the olfactory mucosa.

114.

A 10-year-old  child had the mantoux tuberculin  test   administered.  48  hours later  a  papule  up  to  8 mm  in  diameter appeared  on  the   site  of  the   injection. What type of hypersensitivity reaction developed after the tuberculin injection?

 

Explanation

The Mantoux skin test should be read between 48 and 72hrs after administration. The basis of reading  is the presence or absence of induration, which may be determined by inspection and by palpation. A record should also be made of formation of vesicles, bullae, lymphangitis, ulceration and necrosis at the test site. The formation of vesicles, bullae or necrosis at the test site indicates positive result. A negative mantoux result usually signifies that the individual has never been exposed to Mycobacterium tuberculosis i.e. absence of cell mediated immunity to tuberculin.

Type IV (cell mediated, delayed): antibody-independent T-cell mediated reactions e.g. positive mantoux reaction (tuberculin test), hashimoto’s thyroiditis or transplant rejection etc.

115.

Vitamin  B1  deficiency causes disturbance   of   oxidative    decarboxylation  of  α-ketoglutaric acid.  This  leads  to the  impaired synthesis  of  the  following coenzyme:

 

Explanation

        Thiamine (vitamin B1): thiamine pyrophosphate (TPP) is the biologically active form of the vitamin, formed by the transfer of a pyrophosphate group from ATP to thiamine. Biological role of TPP: it is a component of pyruvate dehydrogenase and α-ketoglutarate dehydrogenase complexes catalyzing the reactions of oxidative decarboxylation of pyruvate and α-ketoglutarate (kreb’s cycle) i.e. it promotes energy formation from carbohydrates and lipids. It’s also a component of transketolase (pentose phosphate pathway of glucose oxidation) essential for fats and nucleic acids synthesis.

Pyruvate to acetyl CoA + CO2 reaction

            If pyruvate dehydrogenase cannot function properly due to vitamin B1 deficiency, then pyruvate will be accumulated in blood because it can’t be broken down.

116.

On the ground  of clinical presentations    a    patient   was   prescribed   pyridoxal phosphate. This medication is recommended for correction of the following processes:

Explanation

Vitamin B6 (pyridoxine): converted to pyridoxal phosphate (PLP), a cofactor used in transamination (e.g. in ALT and AST), decarboxylation reactions, glycogen phosphorylase. Synthesis of cystathione, heme, niacin (Vit. B3), histamine and neurotransmitters including serotonin, epinephrine, norepinephrine, dopamine and GABA. Deficiency produces convulsions, hyperirritability, peripheral neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic anemia due to impaired hemoglobin synthesis and iron excess.

117.

A  patient  with  clinical  presentations  of immunodeficiency has  undergone immunological tests. They revealed  significant  decrease  in  number   of  cells  that form   rosettes  with  sheep   erythrocytes. What   conclusion   can  be  drown  on  the ground  of the analysis data?

 

Explanation

Erythrocyte (RBC) rosetting is a phenomenon seen through a microscope where RBCs are arranged around a central cell to form a cluster that looks like a flower. This formation occurs due to an immunological reaction between an epitope on the central cells surface and a receptor or antibody on a red blood cell. The presence of erythrocyte resetting can be used as a test for T cells. It is used in the identification of T cells where a T cell CD2 surface protein is bound to a sugar based CD58 homologue on the surface of a sheep RBC. Because the CD58 homologue is only present on the surface of sheep RBCs, other species’ RBCs cannot be used in this type of resetting. Therefore, a decrease in the number of cells that form rosettes with sheep’s RBCs indicates a decrease in T-lymphocyte level.

118.

A  man  had  worked   in  a  coal  mine  for  over   20  years.  After   his  death autopsy   revealed    that   his   lungs   were dense,  grayish-black  and  had  large  areas of neogenic  connective tissue  containing a lot of macrophages with black  pigment in the cytoplasm.  What  is the most likely diagnosis?

Explanation

Anthracosis also known as Coal workers’ pneumoconiosis or black lung disease; it is caused by lung exposure to coal dust. It is common in coal miners and others who work with coal. Inhaled coal dust progressively builds up in the lungs and is unable to be removed by the body; this leads to inflammation, fibrosis and in worse cases necrosis.

Alveolar macrophages remove inhaled particulate matter from the air spaces and red blood cells (RBCs) from the septum of alveoli. They are unusual in that they function both in the connective tissue of the septum (alveolar wall) and in the air space of the alveolus (surface of alveolar cells). In air spaces they scavenge the surface to remove inhaled particulate matter (e.g. dust, pollen, pathogens), thus giving them one of their alternate names – Dust cells. They also phagocytose infectious organisms such as Mycobacterium tuberculosis. Other macrophages remain in the septal connective tissue, where, filled with accumulated phagocytized material, they may remain for much of an individual’s life. Thus, at autopsy, the lungs of urban dwellers as well as smokers will usually show many alveolar and septal macrophages filled with carbon particles, anthracotic pigment and birefringent needle-like particles of silica.

119.

Autopsy   of   a   man    who    died from sepsis revealed a phlegmonous inflammation in the femoral bone of lower extremity.  The   inflammation  was  seen in  the   bone   marrow,   haversian   canals and  periosteum. There  were  also  multiple abscesses underneath the periosteum; the  surrounding soft  tissues  of the  thigh were also affected by the phlegmonous inflammation. What  pathological process is it?

Explanation

Osteomyelitis is the inflammation of bone caused by pyogenic organisms. Acute osteomyelitis is an infection of the bone of less than two weeks’ duration, which typically spreads hematogenously (acute hematogenous osteomyelitis). A delay in diagnosis may cause growth disturbance, deformity or even death. It typically affects the long bones (femur and tibia are the most commonly affected). Pathogenesis: preexisting focus/exogenous infection → infective embolus enters nutrient artery → trapped in a vessel in metaphysis and blocks the vessel → active hyperemia and polymorphonuclear cell exudates → hyperemia and immobilization causes decalcification proteolytic enzymes destroy bacteria and medullary elements → the debris increase and intramedullary pressure increases → follows paths of least resistance → passes through haversian canal and Volkmann canal → local cortical necrosis → enter subperiosteal space → strips periosteum → perforation of periosteum/reach joint by piercing capsule → enters soft tissue and may drain out.

120.

After     the    prior     sensibilization an experimental animal was given a subcutaneous  injection   of   an   antigen. The   place   of  injection   exhibited   a  fibrinous   inflammation with  alteration  of the  vessel  walls, basal  substance   and  fibrous  structures of the  connective tissue in form  of mucoid  and  fibrinoid  swelling and necrosis. What  immunological reaction is it?

Explanation

Type I (Immediate, Anaphylaxis, Reagin): IgE (immunoglobulin E)-dependent activation of mast cells/basophils, usually accompanied by eosinophilia e.g. urticaria (hives), hay fever, asthma (wheezing), rhinitis and conjunctivitis (stuffy nose and itchy eyes; usually seasonal)

121.

While  examining   the  oral  cavity  a stomatologist revealed  inflammation of papillae   on  the   border  of  the   median and posterior third of the back of tongue. What papillae are inflamed?

Explanation

krushkrok No89 (2011)

Lingual papillae cover the dorsal surface of the tongue anterior to the sulcus terminalis of the tongue. 4 types:

* Circumvallate papillae: large, dome-shaped structures that reside in the mucosa just anterior to the sulcus terminalis . It divides the tongue into anterior 2/3 and posterior 1/3.  Human tongue has 8-12 of it. It has taste buds.

* Filiform papillae: smallest and most numerous. No taste buds, serve only a mechanical role, distributed over the entire anterior dorsal surface. They are the ones that will be coated since they are numerous and serve mechanical role.

* Fungiform papillae: mushroom shaped, have taste buds

* Foliate papillae: occur on the lateral edge of the tongue.

Taste buds are present on fungiform, foliate and circumvallate papillae.

122.

Autopsy   of   a   50-year-old    man revealed  the  following  changes:  his right lung was moderately compact  in all parts, the  dissected  tissue  was found  to  be  airless, fine-grained,  dryish. Visceral pleura had  greyish-brown layers  of fibrin. What is the most likely diagnosis?

Explanation

      

123.

In   the   pubertal  period    cells   of the  male  sexual  glands  start   producing the   male   sexual   hormone  testosterone that  is responsible for  formation of  the secondary  sexual  characters. What  cells of  the  male  sexual  glands  produce this hormone?

Explanation

Early in male development, mesenchyme separating the seminiferous cords gives rise to leydig (interstitial) cells that produce testosterone to stimulate development of the indifferent primordium into a testis. Leydig cells are large, polygonal, eosinophilic cells that typically contain lipid droplets. Leydig cells differentiate and secrete testosterone during early fetal life. Secretion of testosterone is required during embryonic development, sexual maturation and reproductive function:

·        In the embryo, secretion of testosterone and other androgens is essential for the normal development of the gonads in the male fetus.

·        At puberty, secretion of testosterone is responsible for the initiation of sperm production, accessory sex gland secretion and development of secondary sex characteristics.

·        In the adult, secretion of testosterone is essential for the maintenance of spermatogenesis and of secondary sex characteristics, genital excurrent ducts and accessory sex glands.

124.

Examination  of  a  patient revealed overgrowth  of   facial   bones    and   soft tissues, tongue  enlargement, wide interdental spaces  in the  enlarged dental arch. What changes of the hormonal secretion  are the most likely?

Explanation

These manifestations describe Acromegaly. Acromegaly is the disorder characterized by the enlargement, thickening and broadening of bones, particularly in the extremities of the body. It is due to hypersecretion of growth hormone (somatotropic hormone) in adults after the fusion of epiphysis with shaft of the bone. Adults develop acromegaly with increased lateral bone growth (e.g. hands, feet, jaw). No linear growth occurs because the epiphyses are fused; characterized by prominent jaw spacing between the teeth; frontal bossing; macroglossia (large tongue). Growth hormone promotes majorly the growth of cartilages since the bones are fused. Growth of cartilages produces the lateral growth in bones. It also promotes growth of muscle and organs.

125. Autopsy of a man, who had been suffering from the multiple bronchiectasis for  5 years  and  died  from  chronic  renal insufficiency, revealed that kidneys were dense  and enlarged, with thickened cortical layer of white colour with greasy lustre. What renal disease might be suspected?  

Explanation

Amyloidosis is the term used for a group of diseases characterized by extracellular deposition of fibrillar proteinaceous substance called amyloid. Systemic amyloidosis contain amyloid associated (AA) protein. It occurs as a complication of chronic infectious or noninfectious inflammatory conditions associated with tissues destruction such as tuberculosis, bronchiectasis, chronic osteomyelitis, chronic pyelonephritis etc. It is typically distributed in solid abdominal organs like liver, spleen, kidneys and adrenals. Morphologically, the kidneys may be normal-sized, enlarged or terminally contracted due to ischemic effect of narrowing of vascular intima. Cut surface is pale waxy and translucent.

126.

Autopsy  of  a  49-year-old   woman who died from chronic renal insufficiency, revealed: kidneys were dense, reduced, multicoloured, with  haemorrhagic areas. Microscopic  examination revealed   some hematoxylin   bodies    in   the   nuclei   of the renal tubule  epithelium; \\\"wire- loop\\\" thickening of  the  glomerular capillary basement membrane; here and there in  the  capillaries  some  hyaline  thrombi and foci of fibrinoid necrosis were present. What is the most likely diagnosis?

 

Explanation

Systemic lupus erythematous (SLE, Libman-sacks disease) is the classic prototype of the multisystem disease of autoimmune origin, characterized by a bewildering array of autoantibodies, particularly antinuclear antibodies. It is characterized principally by injury to the skin, joints, kidney, and serosal membranes. Antinuclear antibody is directed against several nuclear antigens and can be grouped into 4 categories:

·        Antibodies to DNA

·        Antibodies to histones

·        Antibodies to nonhistone proteins bound to RNA

·        Antibodies to nuclear antigens.

SLE is a type III hypersensitivity reaction with formation of immune complexes. It can cause diffuse proliferative glomerulonephritis seen under the light microscope as “wire loop” of capillaries and granular under the immunofluorescence microscopy.

127.

As a result of durative antibiotic therapy a 37-year  old  patient developed intestinal  dysbacteriosis.  What   type   of drugs should be used in order  to normalize intestinal microflora?

Explanation

Eubiotics or probiotics aids the development and repopulation of intestinal microbial flora in the event of diarrhea and during treatment with antibiotics and sulfa drugs. A dietary supplement rich in highly concentrated live active cultures contains select high enzymatic function yeast cultures.

128.

A married couple came to the genetic counseling.  The husband suffers from the insulin-dependent diabetes, the wife is healthy.  What  is the  probability that  this couple will have an insulin-dependent child?

Explanation

129.

An   elderly   female   patient  suffers from the type 2 diabetes mellitus accompanied by  obesity,  atherosclerosis, coronary artery disease. Basal hyperinsulinemia  is  also  present.  What treatment would be the most appropriate?

Explanation

Sulfonylurea are insulin secretagogues because they promote insulin release from the β-cells of the pancreas. The primary drugs used today are the 2nd generation drugs – glibenclamide, glipizide, glimepiride etc. These agents are useful in the treatment of patients who have type 2 diabetes mellitus and cannot be managed by diet alone. Metformin is the only currently available biguanide; its classed as an insulin sensitizer. Acarbose – α glucosidase inhibitor. Butamide (tolbutamide) is also a sulfonylurea but is older and glibenclamide is more potent and used much more commonly. Actrapid (soluble insulin) is fast acting but not a sulfonylurea.

130.

A 32-year-old  patient consulted  a doctor   about   the   absence   of  lactation after  parturition. Such disorder might be explained by the  deficit of the  following hormone:

Explanation

     Prolactin is responsible for lactogenesis. Prolactin is secreted from anterior pituitary gland. It is necessary for the final preparation of mammary glands for the production and secretion of milk. Lactation means synthesis, secretion and ejection of milk.

131.

Preventive  examination  of  a  patient  revealed  an enlarged lymph  node  of metastatic origin on the medial wall of the left axillary crease. Specify the most likely localization  of the primary tumour:

Explanation

Metastases of breast cancer is either local or distant. Local metastases is usually to the lymphatic nodes of breast base, axilla, subclavicular, parasternal nodes. Distant metastases are hematogenic ones, 40-50% to the bones, lungs, and liver.

Cancer of any of the following will metastasize locally through:

            Submandibular salivary gland – submandibular nodes

            Thyroid gland – deep anterior cervical nodes

            Stomach – celiac nodes

            Lungs – visceral thoracic lymph nodes

132. A man suffering from osteochondrosis got acute  pain  in the  abdominal muscles (lateral and  anterior). During   objective examination a physician diagnosticated increased pain sensitivity of skin in the hypogastric region. This pain might be caused by affection of the following nerve:

Explanation

The greatest branches of the lumbar plexus are the femoral and obturator nerves; others include the iliohypogastric nerve, ilioinguinal nerve, genitofemoral nerve, lateral cutaneous nerve and the muscular branches. The iliohypogastric nerve arises from behind the lateral border of the psoas major muscle and runs in between the transverses abdominis and the external oblique muscles. The nerve supplies all abdominal muscles, the skin of hypogastrium and the skin of the gluteal region (its superolateral portion).

133.

Pyeloureterography X-ray photo showed  a renal  pelvis with minor  calyces only  (major  calyces  were  absent). What form of urinary tracts of a kidney was revealed?

Explanation

          The embryonic period or period of organogenesis occurs from the 3rd-8th weeks of development. The kidney come from 3 slightly overlapping kidney systems – pronephros, mesonephros and metanephros. Metanephros is the definitive kidney, it appears in the 5th week. Collecting ducts of the permanent kidney develop from the ureteric bud, the bud dilates forming the primitive renal pelvis. These buds continue to subdivide until 12 or more generations of tubules have formed. The tubules of the second order enlarge and absorb those of the 3rd and 4th generations, forming the minor calyces of the renal pelvis. During further development, collecting tubules of the 5th and successive generations elongate considerably and converge on the minor calyx, forming the renal pyramid. The ureteric bud gives rise to the ureter, the renal pelvis, major and minor calyces.

134. Autopsy   of   a   man    who    died from  influenza   revealed   that   the  heart was slightly enlarged and pastose.  The surface of the incision of myocardium appeared to be pale, with specks. Microscopic  examination revealed   signs  of parenchymatous  adipose   and   hydropic degeneration, edematic stroma with scant lymphocytic and macrophage infiltration; plethoric vessels; perivascular petechial haemorrhages. What type of myocarditis is it?

Explanation

135.

In spite of treatment with cardiotonics and thiazide diuretic  a patient suffering from chronic  cardiac  failure  still presents with edemata and  faces a risk of ascites. What  medication should  be administered in order  to increase  the diuretic  effect of the above mentioned drugs?

 

Explanation

K+ sparing diuretics:

  - aldosterone antagonist: spironolactone, eplerenone

  - inhibit Na+ reabsorption: triamterene

     

The answer is Spironolactone because after the administration of cardiotonics and a thiazide diuretic, if the edema still persists, it is probably due to an increased action of aldosterone on the principal cells in collecting tubule of the kidney. In this case, an aldosterone antagonist will enhance the diuretic effect to prevent the occurrence of ascites. Blocking aldosterone effect prevent further reabsorption of Na+ and H2O which will definitely enhance the diuretic effect. Aldosterone acts on mineralocorticoid receptor → mRNA → protein synthesis (synthesis of Na+ channels). Spironolactone prevents/blocks the synthesis of Na+ channels.

 

136.

Gynecological examination of the uterine cervix in a 30-year-old  woman revealed   some  bright-red lustrous   spots that  easily  bleed  when  touched. Biopsy showed  that  a part  of the  uterine cervix was  covered  with  cylindrical  epithelium with papillary  outgrowths; in the depth  of tissue  the  growth  of glands  was present. What pathology of the uterine cervix was revealed?

Explanation

Erosion of the cervix is a defect in the epithelium covering the vaginal portion of the cervix. It is usually caused by inflammation of the mucous membrane of the cervical canal or less frequently, of the vagina. Irritation by cervical leucorrhea results in maceration and scaling of the epithelium with the formation of small superficial ulcers, bright red in colour that bleed when touched – True erosion. 7 – 10days later, columnar (cylindrical) epithelium growing out of the cervical canal gradually covers the ulcerous surface; the resulting “pseudoerosion” may persist with recurrences for many years.

137.

A  stillborn  child was found  to have thickened skin  resembling  of the  tortoise shell, underdeveloped auricles. Histological examination of skin revealed hyperkeratosis, atrophy  of  the  granular epidermis layer; inflammatory changes were not present. What  is the most likely diagnosis?

Explanation

The word Ichthyosis comes from the Greek word for a fish. It is applied to disorders that share, as their main feature, a dry rough skin with marked scaling but no inflammation. Because these disorders manifest as abnormal differentiation of the epidermis, the term disorders of cornification is preferred to Ichthyosis. Histologically, there is moderate degree of compact eosinophilic orthokeratosis (hyperkeratosis without parakeratosis). The granular layer is reduced or absent (atrophy of the granular epidermis layer) and keratohyalin granules may appear spongy or fragmented on electron microscopy. The spinous layer is of normal thickness. Filaggrin is reduced in involved epidermis and profilaggrin mRNA is unstable in keratinocytes. This is a retention hyperkeratosis, with a normal rate of epidermal turnover. The differential diagnosis includes X-linked Ichthyosis and acquired Ichthyosis.

138. A patient presents with twilight vision  impairment. Which  of  the  following vitamins should be administered?

Explanation

Rhodopsin or visual purple is the photosensitive pigment of rod cells. It is made up of a protein called opsin and a chromophore. Opsin present in rhodopsin is known as scotopsin. Chromophore is a chemical substance that develops colour in the cell. Chromophore present in the rod cells is called retinal. Retinal is the aldehyde of vitamin A or retinol. Vitamin A is the name given to a group of related compounds that include retinol (vitamin A alcohol); retinal (vitamin A aldehyde) and retinoic acid (vitamin A acid). Rod cells are responsible for dim light vision or night vision or scotopic vision.

Impairment of twilight vision is a defective function of rod cells. Therefore, vitamin A is recommended as the first choice.

139.

A female  patient consulted  a doctor about   pain   and   limited   movements  in the   knee   joints.  Which  of  the  following nonsteroid anti-inflammatory drugs should  be administered taking into consideration that  the  patient has a history  of chronic gastroduodenitis?

Explanation

image

The nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of chemically dissimilar agents that differ in their antipyretic, analgesic and anti-inflammatory activities. They act primarily by inhibiting the cyclooxygenase (COX 1 and 2) enzymes that catalyze the first step in prostanoid biosynthesis. This leads to decrease prostaglandin synthesis with both beneficial and unwanted effects. Aspirin is one of the most important NSAID. Its most common side effect is its gastrointestinal (GI) effect. Normally, prostacyclin (PGI2) inhibits gastric acid secretion, whereas PGE2 and PGF stimulate synthesis of protective mucus in both the stomach and small intestine.

Celecoxib is a selective cyclooxygenase 2 (COX-2) inhibitor. Approved for treatment of rheumatoid arthritis, osteoarthritis, acute to moderate pain, also approved for patients with peptic ulcers or gastroduodenitis. This is due to the fact that only COX 1 is responsible for the gastrointestinal protective functions.

140.

Depressions and  emotional insanities result  from the deficit of noradrenalin, serotonin and  other   biogenic  amines  in the brain. Their concentration in the synapses can be increased by means of the antidepressants that  inhibit  the following enzyme:

Explanation

image

Norepinephrine (noradrenaline), epinephrine (adrenaline) and dopamine are catecholamines produced in chromaffin cells of adrenal medulla from tyrosine. The catecholamines are inactivated by oxidative deamination catalyzed by monoamine oxidase (MAO) and by O-methylation carried out by Catechol-O-methyltransferase. The metabolic products of these reactions are excreted in the urine as vanillymandelic acid from epinephrine and norepinephrine; and homovanillic acid from dopamine.

141.

A patient presents with icteritiousness of skin, scleras and mucous membranes. Blood  plasma  the  total  bilirubin is increased,  stercobilin is increased in  feces,  urobilin   is  increased   in  urine. What type of jaundice  is it?

Explanation

image

Hemolytic/Prehepatic Jaundice is the type of Jaundice that occurs because of excessive destruction of RBCs resulting in ↑ blood level of free, Indirect, unconjugated bilirubin. In this condition, the excretory function of the liver is normal. But the quantity of bilirubin ↑ enormously. The liver cells cannot excrete that much excess bilirubin rapidly. Formation of Urobilinogen (stercobilin) ↑ resulting in the excretion of more amount of stercobilin in stool and urine.

Indirect; Hemolytic; Prehepatic

Mixed; Parenchymal; Hepatic

Direct; Obstructive; Mechanic; Posthepatic

Stercobilin (faeces)

        ↑↑↑

Decreases (pale faces)

Absent (clay coloured faeces)

Type of bilirubin in blood

Unconjugated

Conjugated and Unconjugated

Conjugated

·       Gilbert syndrome (familial nonhemolytic Jaundice): Autosomal recessive defect. Impaired UGT activity. Jaundice occurs with fasting, volume depletion, stress, menses.

·

142.

A pathology-histology laboratory received  a vermiform  appendix  up to 2,0 cm thick.  Its serous  membrane was pale, thick and covered with yellowish-green films. The  wall was flaccid, of grayish-red colour.  The  appendix lumen  was dilated and filled with yellowish-green substance. Histological   examination  revealed   that the appendix wall was infiltrated with neutrophils. Specify the appendix disease:

Explanation

Acute appendicitis is the most common acute abdominal condition requiring surgery. Clinico-morphological classification of acute appendicitis includes:

·        Simple appendicitis

·        Superficial appendicitis

·        Destructive forms: phlegmonous appendicitis; phlegmonous-ulcerative appendicitis; apostematous appendicitis and gangrenous appendicitis.

Acute phlegmonous appendicitis occurs with diffuse infiltration of leukocytes (especially neutrophils) in the wall of appendix. Gross appearance: appendix is increased, swollen, tense and markedly congested and covered by fibrinous exudates (yellowish-green films).

143.

While on holiday  in the  countryside a  boy  found  a  spider  with  the  following  morphological  peculiarities: body length   of  2  cm,  round   black  abdomen with  two  rows  of red  dots  on  its dorsal surface,  four pairs of segmented extremities covered with tiny black hairs. Identify this arthropod:

Explanation

krushkrok No143a (2009)krushkrok No143 (2009)

Karakurt spider: the word kara meaning “black” and kurt meaning “worm” comes from the Turkic languages. It is black in colour and is identified by the thirteen (13) spots which are found on its dorsal abdomen. These spots are usually red in colour, but may also be yellow, or orange. The female has a body length of 1 – 2cm (10-20mm), while the male is smaller and reaches 0.5 – 0.8cm (5-8mm) at best. Only the female spider’s bite is dangerous (either for humans or cattle) as the male cannot penetrate the relatively thick epidermis.

144.

As a result of a trauma a patient has developed traumatic shock that led to the following disorders:  AP is 140/90 mm Hg, Ps is 120 bpm. The patient is fussy, talkative, pale. Such state relates to the following shock phase:

Explanation

Pirogov’s stages of shock

* Erectile phase: is characterized by strong motor agitation, sweating, tremor of skeletal muscles, staggering gait, frequent urination, transient increase in blood pressure, heart rate and breath rate increases, body temperature also. Painful impulses reach CNS.

* Torpid phase: decompensation in CNS leads to deep oppression. Patient is motionless, does not answer questions or answers very silently and with long time of delay, reflexes are lowered or absent.

145.

Examination of a patient admitted to the surgical department with symptoms of acute  appendicitis revealed  the following changes in the white blood cells: the total count of leukocytes  is 16 · 109/l. Leukocyte formula:  basophils  - 0, eosinophils  - 2%, juvenile  forms  - 2%,  stabnuclear - 8%, segmentonuclear   -   59%,    lymphocytes  -  25%,  monocytes-   4%.  The  described changes can be classified as:

Explanation

Neutrophilic leukocytosis: increase in neutrophil count. Depending on the proportion between the mature and premature forms of neutrophils, two types of the nuclear shift may be distinguished: to the left, when there is an elevated content of immature forms of neutrophilic granulocytes (myelocytes, metamyelocytes, bands) in the blood; And to the right, when the mature neutrophils with a large number of segments (5 – 6) prevail against a background of younger cells disappearing. The nuclear shift may be subdivided into: regenerative, hyperregenerative, degenerative and regenerative-degenerative shifts.

Regenerative shift develops against a background of mild general leukocytosis, accompanied with elevated content of bands and metamyelocytes (immature forms). This shift results from the reactive leukopoiesis (granulocytopoiesis) activation and is common in suppurative septic processes.

Neutrophils: Stab (band): 1-6%             (8%)↑

                     Segmented: 47-72%         (59%) normal

                     Myelocyte and Metamyelocyte: 0-1%      Juvenile forms (2%)↑

Since there is an elevated content of immature forms of neutrophils, then it is a regenerative left shift.

146. After  a trauma a patient lost ability of elbow extension. This might have been caused  by  dysfunction  of  the  following main muscle:

Explanation

krushkrok No29b (2014)krushkrok No29a (2014)

* Triceps brachii is the chief extensor of the forearm at the humeroulnar joint. Has a long, lateral, and medial head. Inserts on olecranon of ulna bone.

*Infraspinatus muscle: Lateral (external) rotation of the humerus at the glenohumeral joint, also assists in holding the head of the humerus in the glenoid fossa.

*Teres Major muscle: Adduction & medial rotation of the humerus at the glenohumeral joint shoulder joint)

*Subscapularis muscle: Medial (internal ) rotation and adduction of the humerus at the glenohumeral joint, also assists in holding the head of the humerus in the glenoid fossa.

*Levator scapulae muscle: Elevates the scapula.

147.

A  student  came   to  see  a  doctor and  asked  to  administer him  a drug  for treatment of allergic rhinitis that occurs in the period  of linden flowering. What drug may be used?

Explanation

Loratidine : Antihistamine (antiallergic); blocks H1-histamine receptors as well as adrenergic, cholinergic & serotonin-binding recpetors. They do not influence the formation or release of histamine, but rather they competitively block the receptor-mediated response of target tissue.                                                                                            
148.

In  an  embryo  the  process  of dorsal mesoderm segmentation and somite formation  is  disturbed.  What   part   of skin will probably  have developmental abnormalities?

 

Explanation

The embryonic period or period of organogenesis occurs from the third – eighth weeks of development and is the time when each of the 3 germ layers: ectoderm, mesoderm and endoderm, give rise to a number of specific tissues and organs.

Mesoderm: paraxial, intermediate and lateral mesoderm. By the beginning of the 3rd week, paraxial mesoderm begins to be organized into segments. These segments, known as somitomeres, which further organize into somites (42-44 pairs). Somites: sclerotome (tendon, cartilage and bone – vertebrae and rib cage); Myotome (muscles); Dermatome (dermis). From their initial location within the somite, the sclerotome cells migrate medially towards the notochord.
149. A 9-month-old infant is fed with artificial formulas  with  unbalanced vitamin B6     concentration.  The   infant   presents with pellagral  dermatitis, convulsions, anaemia. Convulsion  development might be caused by the disturbed formation of:

Explanation

image           

Vitamin B6 is a cofactor for decarboxylation reactions.       

Certain amino acids undergo decarboxylation that means the removal of their α-carboxyl group resulting in liberation of CO2 and formation of biogenic amines. Biogenic amines are physiologically active substances such as hormones, neurotransmitters etc. decarboxylation of amino acids:

·        Tryptophan → Niacin → NAD+/NADP+

Tryptophan → Serotonin →Melatonin

·        Histidine → Histamine

·        Glutamine → GABA

Glutamine → Glutathione

150.

During  an  experiment the  myotatic reflex has been studied in frogs. After extension in  a  skeletal  muscle  its reflectory contraction was absent. The reason  for  it  might  be  a  dysfunction   of the following receptors:

Explanation

        Muscle spindle s a spindle shaped proprioceptor situated in the skeletal muscle. It is formed by modified skeletal muscle fibers called intrafusal muscle fibers. Muscle spindle gives response to change in the length of the muscle. It detects how much the muscle is being stretched and sends this information to the CNS via sensory nerve fibers. Stimulation of muscle spindle elicits the stretch reflex. Extensor muscles, particularly the antigravity muscles exhibit a severe and prolonged contraction during stretch reflex. Stretch reflex is the reflex contraction of muscle when it is stretched. Also called myotatic or a monosynaptic reflex. It is the quickest of all the reflexes.

151.

During   an  experiment  vagus branches that  innervate heart  are  being stimulated. This  has  stopped conduction of excitement from the atria to the ventricles. The reason  for it are electrophysical changes in the following structures:

Explanation

Atrioventricular (AV) node serves as the gateway for conduction of impulses from the atria to the ventricle. Stimulation of the parasympathetic nerves to the heart (vagus nerve) causes the neurotransmitter acetylcholine to be released at the vagal endings. This neurotransmitter has two major effects on the heart. First, it decreases the rate of rhythm of the sinus node, and second, it decreases the excitability of the AV junctional fibers between the atrial musculature and the AV node, thereby slowing transmission of the cardiac impulse into the ventricles. In the AV node, a state of hyperpolarization caused by vagal stimulation makes it difficult for the small atrial fibers entering the node to generate enough electricity to excite the nodal fibers. A moderate decrease simply delays conduction of the impulse, but a large decrease blocks conduction entirely.

152.

A   man   has   worked   in  an   African  country  for  3 years.  A  month  after his   return   to   Ukraine   he   consulted an    ophthalmologist    and    complained about  eye ache,  eyelid  edema,  lacrimation and temporary visual impairment. Underneath   the    eye   conjunctiva   the doctor  revealed  helminths  30-50 mm long with elongated filiform body. What diagnosis might be suspected?

Explanation

Loa Loa filariasis also known as loiasis or African eyeworm. Humans are infected by the bite of the deer fly (mango fly), chrysops, which deposits infective larvae on the skin. The larvae enter the wound, wander in the body and develop into adults. The females release microfilariae that enter the blood, particularly during the day. There is no inflammatory response to the microfilariae or adults, but a hypersensitivity reaction causes transient, localized, nonerythematous, subcutaneous edema (calabar swellings). The most dramatic finding is an adult worm crawling across the conjunctiva of the eye, a harmless but disconcerting event. The disease is found only in tropical central and west Africa, the habitat of the vector Chrysops.

153.

After   a  disease  a  16-year-old   boy is presenting with  decreased function  of protein synthesis in the liver as a result of vitamin  K  deficiency.  This may cause  disorder of:

Explanation

image

Vitamin K is essential for the formation of various clotting factors in the liver, namely clotting factor II, VII, IX and X; Protein C and S.

Factor II – Prothrombin

Factor VII – Stable factor

Factor IX – Christmas factor

Factor X – Stuart-Prower factor

These factors undergo vitamin K-dependent post-translational modification, whereby a number of their glutamic acid residues are carboxylated to form ɣ-carboxyglutamic acid residues. The ɣ-carboxyglutamyl residues bind calcium ions which are essential for interaction between the coagulation factors and platelet membranes. This oral anticoagulants block epoxide reductase and creation of active form of vitamin K resulting in disturbances in prothrombin and proconvertin synthesis in liver.

154.

In response to a change in body position from horizontal to vertical blood circulation system develops reflectory pressor  reaction. Which  of the  following is its compulsory  component?

Explanation

From horizontal (lying position) to vertical (standing position) will make all blood flow towards the lower extremities, thereby reducing venous return (blood going upwards towards the heart) in the first place. This will definitely ↓ cardiac output (C.O) → ↓blood supply to brain (this can lead to fainting). Then there is reflex vasoconstriction to increase venous return to heart, in the absence of any pathology.

155. Life   cycle   of   a   cell   includes   a process   of  DNA   autoreduplication.  As a result of this process monochromatid chromosomes become  bichromatid. This phenomenon is observed within the following period  of the cell cycle:

Explanation

Somatic cell division is a cyclic process divided into two phases: mitosis (M phase) and interphase. Three other phases, Gap 1 (G1); synthesis phase (S) and Gap 2 (G2) further subdivide interphase. M phase is followed by G1.

M phase: karyokinesis – division of the nucleus into two daughter nuclei.

                  Cytokinesis – division of the cell into two daughter cells.

G1: a period in which no DNA synthesis occurs.

Period of cell growth S or DNA synthesis phase follows G1 phase. The DNA of the cell is doubled. The S phase is followed by a period in which no DNA synthesis occurs, a second gap or G2 phase. A cell that leaves the cycle in G1 phase to begin “terminal” differentiation enters the G0 phase, (“O” stands for “outside” the cycle).

 
156. As a result of a road accident a driver has gotten  a trauma. Now he is in shock condition and presents with a decrease in daily diuresis down to 300 ml. What is the main pathogenetic factor  of such alteration in the diuresis?

Explanation

The usual cause of shock is a decreased cardiac output, which may be due to: heart failure (cardiogenic shock); or too little venous return. The reasons for too little venous return are; reduction in blood volume following the loss of blood or the loss of fluid (in connection with burns, severe vomiting) or peripheral vasodilation and hence too much blood in the periphery. All these leads to a decrease in blood pressure.

        ↓blood volume → vasoconstriction → disturbance of tissue metabolism → vessel damage → ↑vasodilatation and filtration into interstitium → ↓blood volume → ↓blood pressure → O2 deficiency and acidosis → damage of myocardium → ↓cardiac output → ↓blood pressure → ↓blood supply to kidney → ↓diuresis.

157.

Examination  of  a  patient revealed autoimmune haemolytic anaemia (cytotoxic type). What substances act as antigenin the II-type allergic reactions?

Explanation

158.

A patient suffers from the haemorrhagic syndrome  that  shows itself in frequent nasal bleedings, posttraumatic and    spontaneous   intracutaneous   and intra-articular haemorrhages. After a laboratory study a patient was diagnosed with the type B haemophilia. This disease is provoked by the deficit of the following factor of blood coagulation:

Explanation

Hemophilia is a group of sex-linked inherited blood disorders characterized by prolonged clotting time. However, the bleeding time is normal. Usually, it affects the males, with the females being the carriers. Hemophilia occurs due to lack of formation of prothrombin activator. That is why the coagulation time is prolonged. The formation of prothrombin activator is affected due to the deficiency of factors VIII, IX or XI.

   Types of hemophilia: 

*Hemophilia A or classic hemophilia - deficiency of factor VIII (X-LINKED RECESSIVE)

*Hemophilia B or Christmas disease - deficiency of factor IX (X-LINKED RECESSIVE)

*Hemophilia C or factor XI deficiency (AUTOSOMAL RECESSIVE)

It will be passed to the sons – the mother is the carrier.

159. After  a craniocerebral trauma a patient lost the ability to execute learned purposeful movements (apraxia). The injury is most likely localized in the following region of the cerebral cortex:l

Explanation

        Apraxia is defined as a cognitive motor disorder in which the patient loses the ability to accurately perform learned, skilled actions. Apraxia is primarily a condition that localized to the dominant (usually left) hemisphere of the brain. In particular, lesions of supramarginal gyrus and underlying white matter of the left parietal lobe have been implicated to cause apraxia.

160.

A  58-year-old   patient suffers  from the  cerebral  atherosclerosis. Examination revealed  hyperlipoidemia. What  class of lipoproteins will most  probably  show increase  in concentration in this patient’s blood serum?

Explanation

krushkrok No13a (2014)

Atherosclerosis is a multifactorial disease that affects the intima of elastic arteries. The disease is characterized by intramural deposits of lipids, proliferation of vascular smooth muscle cells and fibroblasts and accumulation of macrophages. The risk is correlated with elevated low density lipoprotein (LDL), formed from the catabolism of very low density lipoprotein (VLDL) to a cholesterol ester-protein core that carries some 70% of the total serum cholesterol. Atheroma is specifically associated with high blood LDL levels (as well as total cholesterol levels). Risks is inversely related to the HDL levels, perhaps because high density lipoprotein (HDL) helps clear cholesterol from vessels.

HDL – Good cholesterol

LDL – Bad cholesterol

161. A patient consulted a physician about muscle rigidity, constrained movements, permanent arm  tremor. The  patient was diagnosed  with Parkinson’s disease. What preparation should be administered?

Explanation

image

Levodopa is a metabolic precursor of dopamine. It restores dopaminergic neurotransmission in the corpus striatum by enhancing the synthesis of dopamine in the surviving neurons of the substantia nigra. Parkinsonism results from insufficient dopamine in specific regions of the brain, attempts have now been made to replenish the dopamine deficiency. Dopamine itself does not cross the blood-brain barrier, but its immediate precursor (levodopa) is actively transported into the CNS and is converted to dopamine in the brain.

162.

A  patient with  coronary   artery  disease  was  admitted to  the  cardiological department.  For  stenocardia prevention a drug from the group  of β-adrenoceptor blockers  was administered. What  drug  is it?

Explanation

image

β1-adrenoblocker (cardioselective) – Metoprolol: blocks β1-adrenoreceptors of the heart. Atropine sulphate - M cholinoblocker; Morphine hydrochloride – Narcotic analgesic; Oxytocin - Pituitary hormone (female sex hormone); Furosemide - Loop diuretic

163.

A  28-year-old   female  patient consulted a  gynecologist   about   sterility. Examination revealed underdeveloped ovaries and uterus,  irregular menstrual cycle.   Analysis   of   the   sex   chromatin revealed  2 Barr’s bodies  in most  somatic cells. What  chromosome disease  is most likely?

Explanation

Barr body is an inactive X-chromosome. A normal female has one barr body XX, a normal male has no barr body XY.

Trisomy XXXX (only one X is active in a female; therefore, 2 barr bodies)

KlinefelterXXY (one barr body)

Turner’s – XO (no barr body)

Edward and Patau involves autosomal chromosomes and not sex chromosomes.

164.

A patient with drug intoxication presented with the dryness of oral mucous membrane  and   mydriatic   pupils.   Such action  of this drug  is associated  with the following effect:

Explanation

Muscarinic receptors belong to the class of G protein-coupled receptors. These receptors, in addition to binding Acetylcholine, it also recognizes muscarine – an alkaloid that is present in certain poisonous mushrooms. Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

Therefore, a block of this receptor will produce opposite effects as listed in the question (e.g mydriatic pupils, dryness of oral mucous membrane)

165.

A    newborn   develops    dyspepsia after   the   milk  feeding.   When   the   milk is substituted by the  glucose  solution the  dyspepsia  symptoms  disappear. The newborn  has the subnormal activity of the following enzyme:

Explanation

       Lactase (β-galactosidase) cleaves lactose (in milk) producing galactose and glucose. Hereditary deficiencies of lactase have been reported in infants and children with dissacharide intolerance. Treatment for this disorder is to reduce consumption of milk. This is seen when the milk is substituted by glucose solution.

166.

A man presents with increased  heart rate, mydriatic pupils, dry mouth. This condition results  from  the  activation   of the following system of function  regulation:

Explanation

Muscarinic receptors belong to the parasympathetic system. Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

image

Block of M-cholinoreceptor or activation sympathetic nervous system will produce the opposite effects as described in the question (mydriatic pupils - opposite to miosis; dry mouth - opposite to increase salivation)

 
167.

A patient with a limb fracture must be administered a depolarizing drug from the myorelaxant group for the purpose of a short-time surgery. What drug is it?

Explanation

Dithylinum is a neuromuscular blocking drug (myorelaxants). It attaches to the N-cholinoreceptor depolarizing the junction and providing a constant stimulation of the receptor. The continued binding of the depolarizing agent renders the receptor incapable of transmitting further impulses. They are used to relax muscles during surgery.

168.

A patient suffering from chronic bronchitis    takes   a   synthetic   mucolytic drug that  facilitates  the  sputum  thinning. What drug is it?

Explanation

Acetylcysteine is a synthetic mucolytic (expectorant). It has sulfhydryl group that tear disulfide connections, helps mucosa expelling and reduces the viscosity of mucus. Besides this acetylcysteine is an antioxidant and cardioprotector. It increases bronchial secretion or reduce its viscosity (sputum thinning), facilitating its removal by coughing, they are believed to “loosen” cough which becomes less tiring and more productive.

169.

A patient with massive burns developed acute renal insufficiency characterized    by    a    significant     and rapid  deceleration of  glomerular filtration. What is the mechanism  of its development?

Explanation

       Massive burns leads to hypovolemia and decreases general blood volume in circulation. This decrease in blood volume, decrease perfusion to all organs in the body. Decrease in renal perfusion (renal blood flow) will decrease glomerular filtration rate (GFR).

170. A patient with severe course of respiratory  viral infection  presented with clinical signs of progressing  heart  failure  that led to his death in the 2nd week of disease. Autopsy revealed   that  the  heart   cavities  were  significantly  dilated,   the   heart was  flabby.  Histological   examination  of the myocardium revealed  microvascular plethora  and  diffuse  stroma   infiltration with  lymphocytes   and  histiocytes.  What is the most likely diagnosis?

Explanation

Myocarditis is inflammation of the heart myocardium. Microvascular plethora and diffuse stroma infiltration with lymphocytes and histiocytes are indicative of an inflammatory process taking place in the heart. Heart failure, dilated heart cavities are complications of myocarditis.

171.

During  the regular  sanitary-epidemiological inspection  of a pharmacy, the bacteriological analysis of air was performed. The air was found to have bacilli, yeast fungi, hemolytic streptococci, micrococci. Which of the detected microorganisms indicate  the direct epidemic danger?

Explanation

Group A β-hemolytic streptococci (Streptococcus pyogenes) are one of the most important human pathogens. They are the most frequent bacterial cause of pharyngitis and a very common cause of skin infections. They adhere to pharyngeal epithelium via pili covered with lipoteichoic acid and M protein. The mode of spread of the hemolytic streptococcus is complex and dependent on a number of interrelated factors such as the presence of carriers, droplets, droplet nuclei and dust; viability, infectivity and virulence of airborne streptococci; ventilation; ultraviolet radiation; and population density and susceptibility. In general, group A streptococci are spread by contact. Such contact may be direct as the transfer of Streptococci from the nose to the hands to the surgical wound or airborne. Studies have shown that they produce direct epidemic danger.

172.

A man  with an injury  in the  nuchal region (regio nuchae) was admitted to the resuscitation department. What  muscle occupies this region?

Explanation

krushkrok No172a (2009)krushkrok No172 (2009)

Trapezius is a flat, triangular muscle, whose base is facing the spinous processes of the vertebrae. It resides in the upper part of the back and the occiput. The right and left trapezius muscles together form a trapezoid.

Origin: the external occipital protuberance, the superior nuchal line, the ligamentum nuchae and the spinous processes of vertebrae C7 - T12.

Insertion: the spine of the scapula, the acromion and the lateral third of the clavicle.

Action: adducts, rotates, elevates and depresses the scapula.

Nuchal region – neck region

173.

A section  of the  left lung was found to have  an area  of dense  red  tissue.  The area was cone-shaped, stood out distinctly from  the  healthy  tissue,  with its base  directed  to the pleura.  The dissected  tissue was granular, dark-red. What  is the  most likely diagnosis?

Explanation

Infarction is an area of ischemic necrosis within a tissue or an organ, produced by occlusion of either its arterial supply or its venous drainage. Infarction of the lungs: embolism of the pulmonary arteries may produce pulmonary infarction, though not always. The pulmonary infarcts are classically wedge-shaped or cone shaped with base on the pleura (periphery) hemorrhagic, variable in size and most often in the lower lobes. Cut surface is dark purple or red and it may show the blocked vessel near the apex of the infracted area. Old organized and healed pulmonary infarcts appear as retracted fibrous scars. The characteristic feature is coagulative hemorrhagic necrosis of the alveolar walls.

174.

An  animal  has  an  increased tonus of   extensor   muscles.   This   the   result of    intensified    information   transmission   to   the   motoneurons  of  the   spinal cord through the following descending pathways:

Explanation

Vestibular nuclei receive impulses concerned with muscle tone and posture from vestibular apparatus and cerebellum. Vestibular nuclei in turn convey the impulses to different parts of the body through the anterior and lateral vestibulospinal tracts. Vestibulospinal tracts are concerned with adjustment of position of head and body during angular and linear acceleration; maintenance of muscle tone and posture; position of head and body during acceleration. Therefore, increase transmission of impulse through this tract leads to increase tone. Extensor muscles are also for balance (connected to vestibular apparatus). The inputs from the otolith organs project mainly to the lateral vestibular nucleus, which in turn sends axons in the lateral vestibulospinal tract to the spinal cord. The input from this tract exerts a powerful excitatory influence on the extensor (antigravity) muscles. When hair cells in the otolith organ are activated, signals reach the medial part of the ventral (anterior, motor) horn. By activating the ipsilateral (same side) pool of motor neurons innervating extensor muscles in the trunk and limbs, this pathway mediates balance and the maintenance of upright posture.

175. Following  exposure   to  radiation a lot  of  mutant cells  appeared in  a  patient.  Some  time  later  most  of them  were detected and  destroyed by the  following cells of the immune system:

Explanation

When a T-cell encounters an invading virus, mutant cells, cancerous cells or transplanted cells it begins to divide, forming four different types of T-cell, T-killer cells (CD8); helper T-cells (CD4); suppressor T-cells and memory T-cells. Cytotoxic T cells (T killers) are activated by helper T cells; they circulate through blood, lymph and lymphatic tissues and destroy the invading organisms by attacking them directly. Cytotoxic T cells destroy cancer cells, transplanted cells, mutant cells and even body’s own tissues which are affected by the foreign bodies, particularly viruses; because of this, the cytotoxic T cell is called killer cell.
176.

A   65-year-old   man   has   purulent abscess  on  his  neck.  Analyses   revealed a culture  of gram-positive cocci with plasmocoagulase activity. This culture relates most likely to:

Explanation

Staphylococcus aureus is a gram positive cocci that appear in clusters. It causes:

·        Inflammatory disease  like skin infections, organ abscesses

·        Toxin mediated disease like the toxic shock syndrome (TSST-1)

·        MRSA (methicillin-resistant Staphylococcus aureus) infection.

Staphylococcus aureus is a β-hemolytic bacteria i.e. they form a clear zone of hemolysis on blood agar. They are catalase and coagulase (plasmocoagulase) positive.

177.

In clinical practice  tuberculosis is treated with  isoniazid  preparation - that is an  antivitamin able  to  penetrate into the  tuberculosis bacillus.  Tuberculostatic effect  is induced  by the  interference with replication processes  and oxidation- reduction reactions due to the buildup  of pseudo-coenzyme:

Explanation

Isoniazid is the hydrazide of isonicotinic acid and is a pyridine. Pyridine occurs in many important compounds including  azines and the Vitamins Niacin(B3) and Pyridoxine(B6). Therefore, isoniazid can be interfered with Vit.B3, B6 and even B1 metabolism by competing with them.

Isoniazid is a first line antituberculosis drug that inhibits the synthesis of mycolic acid. Vit B6 is needed for the transformation of tryptophan to Vit.B3. NAD is a coenzyme of Vit B3.

Adverse reaction of Isoniazid: peripheral neuritis, optic neuritis, hepatitis and idiosyncratic hepatotoxicity.
178.

A newborn child was found  to have reduced intensity of sucking, frequent vomiting, hypotonia. Urine and blood exhibit increased  concentration of citrulline. What metabolic process is disturbed?

Explanation

image

In urea or ornithine cycle, the first two reactions leading to the synthesis of urea occur in the mitochondria, whereas the remaining cycle enzymes are located in the cytosol. The first reaction is formation of carbomoyl phosphate and the second reaction is formation of citrulline. Ornithine and citrulline are basic amino acids that participate in the urea cycle. The release of the high energy phosphate of carbomoyl phosphate as inorganic phosphate drives the reaction in the forward direction. The reaction product – Citrulline is transported to the cytosol where it condenses with aspartate to form argininosucinate. Increased concentration of citrulline in urine and blood indicates a defect in ornithine or urea cycle.

179.

Vagus nerves of an experimental animal have been cut on the both sides. What respiratory changes will result from this?

Explanation

180. Before   tooth   extraction  a  patient was  advised  to  take  a  certain   drug  for haemorrhage prevention. What drug was advised?

Explanation

Vikasol (Menadioni natrii bisulfis) is a synthetic water soluble analogue of Vitamin K. it’s a coagulant. It participates in the formation of prothrombin. It promotes normalization of blood clotting. Indications include acute hepatitis, parenchymal and capillary bleeding, obstructive jaundice.

181. A patient who has been taking a drug for  a long  time  cannot  abruptly stop  its use, because  this may lead to psychic and somatic dysfunctions. Name the syndrome of different disorders caused by a drug withdrawal:

Explanation

Abstinence: apart from drugs that are usually recognized as producing dependence, sudden interruption of therapy with certain other drugs also results in adverse consequences, mostly in the form of worsening of the clinical condition for which the drug was being used e.g. Acute adrenal insufficiency may be precipitated by abrupt cessation of corticosteroid therapy; frequency of seizures may increase on sudden withdrawal of an antiepileptic etc. These manifestations are also due to adaptive changes and can be minimized by gradual withdrawal.

182. A  45-year-old  patient suffers  from neurosis characterized by irritability, sleeplessness,   motiveless   anxiety.   What drug would eliminate all the symptoms?

Explanation

All of the benzodiazepines used to treat anxiety (tranquilizers) have some sedative properties and some can produce hypnosis (artificially produced sleep) at higher doses. Their effects have been shown to be mediated by the α1-GABAA receptors. Benzodiazepines are the most widely used anxiolytic drugs e.g. Diazepam, lorazepam, nitrazepam, clonazepam etc. They are also used to treat neurosis.

183.

After  taking poor-quality food a patient  developed repeated  episodes   of  diarrhea. On the next day he presented with decreased arterial  pressure, tachycardia, extrasystole. Blood pH is 7,18. These abnormalities were caused by the development of:

Explanation

Acidosis is the reduction in pH (increase in H+ concentration) below normal range. pH is less than 7.35; it is produced by:

·        Increase in partial pressure of CO2 in the body.

·        Decrease in HCO3- concentration.

Alkalosis is the increase in pH (decrease in H+ concentration) above normal range. pH is greater than 7.45; it is produced by:

·        Decrease in partial pressure of CO2 in the body.

·        Increase in HCO3- concentration.

Each of these two disorders has respiratory and non-respiratory forms. The non-respiratory form is divided into metabolic and excretory(non-gaseous).

·        Respiratory acidosis is the acidosis that is caused by alveolar hypoventilation e.g. airway obstruction due to bronchitis or lung diseases (pneumonia).

·        Respiratory alkalosis is caused by alveolar hyperventilation e.g. hypoxia in high altitude.

·        Non-respiratory:

-Metabolic acidosis is characterized by excess accumulation of organic acids such as lactic acid, ketoacids and uric acid formed by normal metabolism e.g. in Diabetes mellitus or extreme/prolonged exercise.

-Excretory/Non-gaseous acidosis may develop in impaired renal H+ excretion related to increased loss of bicarbonate in urine; diarrhea causes acidosis by the loss of bicarbonate with faeces.

-Excretory/Non-gaseous alkalosis: vomiting (loss of gastric acid), increased metabolism of lactate and citrate (turns into bicarbonate and water), long-term use of thiazides and loop diuretics.

      It is excretory/non-gaseous alkalosis because of the frequent vomiting.

184.

Which muscle contraction will be observed in  the  upper   extremity during holding  (not  moving)  a load  in a certain position?

Explanation

         Muscle contraction is classified into 2 types: Isotonic and Isometric.

·        Isotonic contraction: the tension in the muscle remains the same but the length of the muscle fiber is changing (Iso = same; tonic = tension) e.g. simple flexion of arm, where shortening of muscle fibers occurs but the tension does not change.

·        Isometric contraction: the length of muscle fibers remains the same but the tension is increased e.g. pulling any heavy object when the muscles become stiff and strained with increased tension but the length does not change. Holding (but not moving) – length does not change.

185. A patient has lost skin sensitivity  in the region of the medial surface of his shoulder. This  is the  result  of dysfunction of the following nerve:

Explanation

Medial cutaneous nerve of arm (medial brachial cutaneous nerve) is a branch of brachial plexus from the infraclavicular part. It’s a thin nerve that arises from the medial cord of brachial plexus and supplies the skin of medial area of arm. Medial antebrachial cutaneous nerve supplies the anteromedial area of forearm.

186.

Examination of a young woman revealed   a  tumour  up  to  3  cm  in  diameter  in   form   of   a   knot    localized along  the  acoustic  nerve.  The  tumour is homogenous,  soft  and  elastic,  of  pink- and-white colour. Microscopically  the tumour contains  clusters of cells with oval nuclei.  Fibrous  cell clusters  form  regular structures made  up  by  parallel  rows  of regularly  oriented cells arranged in form of  a  palisade.  Zones   between the  rows of cells are acellular and homogenous (Verocai bodies).  What tumour is it?

Explanation

image

Neurinoma or Schwannoma is a benign tumor of peripheral nervous system. It is formed of spinder-like cells with rod-shaped nuclei. The cells and fibers form rhythmical structures. An acoustic neurinoma is a benign tumor that may develop on the hearing and balance nerves (CNVIII vestibulocochlear nerve) near the inner ear. The tumor results from an overproduction of Schwann cells – small sheet-like cells that normally wrap around nerve fibers like onion skin and help support the nerves.

187. A  patient with  myocardial   infarction was admitted to the cardiological department. For  pain  relief  it  was decided   to   potentiate  fentanyl   action   with  a  neuroleptic.  Which  of  the  following  neuroleptics is the  most  suitable  for neuroleptanalgesia?

Explanation

        Droperidol is often combined with a potent narcotic analgesic such as fentanyl to produce neuroleptanalgesia. It is used for neuroleptanalgesia because of its quick effect (action), short duration of action, myorelaxant and antihypertensive effects. Droperidol has quick and short effects, produces hypotension and myorelaxantia.

         Fentanyl + Droperidol = Talomonal (neuroleptanalgesia)

188.

Treatment course of bacterial pneumonia included  benzylpenicillin sodium  salt.  What  is the  mechanism   of its antimicrobial action?

Explanation

            Penicillins inhibit the synthesis of bacterial cell walls and are considered bactericidal too. They bind penicillin binding proteins (transpeptidases) and block transpeptidase cross-linking of peptidoglycan in cell wall. They also activate autolytic enzymes. Benzylpenicillin sodium is a short acting penicillin.     

The cephalosporins are β-lactam antibiotics that are closely related both structurally and functionally to the penicillins. Cephalosporins like the penicillns, inhibit bacterial cell wall synthesis and are considered bactericidal against susceptible organisms.

         

189.

A 49-year-old driver complains about unbearable constricting   pain  behind  the breastbone  irradiating to  the  neck.  The pain  arose  2 hours  ago.  Objectively:  the patient’s   condition  is  grave,  he  is  pale, heart  tones are decreased. Laboratory studies  revealed  high activity  of creatine kinase and LDH1.  What disease are these symptoms typical for?

Explanation

Lactate dehydrogenase (LDH) is an enzyme in cardiac cells which can serve as a marker for injured myocardial cells as it leaks out of damaged cell membranes into the bloodstream. It catalyzes the conversion of pyruvate to lactate (a reversible reaction). It has five (5) isoenzymes (isoenzymes catalyze same reaction), but only LDH1 is found in the myocardium.

LDH1 – heart, RBCs and brain; LDH2- reticuloendothelial system; LDH3- lungs; LDH4- kidneys, placenta and pancreas; LDH5- liver and striated muscle.

190.

A  60-year-old   patient  presents with weakened peristaltic activity of the bowels. Which of the following foodstuffs would stimulate peristalsis most of all?

 

Explanation

The various cereals used for bread when coarsely ground contain a large proportion of the external envelope of the grains, which is more or less hard and rough; and by its presence in the intestine it stimulates peristalsis through mechanical irritation. For the above reasons, the following articles of diet tend to overcome constipation: coarse Graham bread, Rye bread, Oatmeal, Brown or “wholemeal” bread, Boston brown bread, shredded wheat.

191.

After  inoculation of the material obtained from  the  pharynx  of an angina patient onto the blood-tellurite agar, grey colonies  could  be  observed.   They  were  4-5 mm in diameter, radially  striated (in form  of  rosettes). Microscopical   examination  revealed  gram-positive bacilli  with clavate  swollen ends arranged in form of wide-spread fingers. Identify  these  microorganisms:

Explanation

Diphtheria bacteria (Corynebacterium diphtheria) is Gram positive, pleomorphic, often club-shaped rods and are arranged in palisades or in V (at an angle) or L-shaped formations. Media used for isolation are Tellurite agar & Lὄffler medium. Lὄffler nutrient medium consists of coagulated serum & nutrient broth. Selective indicator medium containing tellurite are used in selective culturing. K tellurite is used to inhibit the accompanying flora.

192. A  microspecimen of the  submandibular  salivary  gland  shows some  basketshaped   cells   concentrated  around  the acines and excretory ducts. These cells surround  bases  of  the  serous  cells  and are  called  myoepitheliocytes. These  cells relate  to the following tissue:

Explanation

Myoepithelial cells are contractile cells that embrace the basal aspect of the acinar secretory cells in salivary glands. Myo – Muscle

193.

It  was  established that  agglutination  of  the  recipient’s  blood  erythrocytes had  been   caused   by  the  standard  sera from  the  I and  II groups.  Serum  from the  III group  as well as anti-Rh serum hadn‘t provoke any agglutination. Which blood  group  and  rhesus  is allowed  to be transfused this recipient?

Explanation

image

Blood group O(I): no antigens, therefore no agglutination.

Blood group A(II): A antigen, agglutinate with blood group B(III) and O(I).

Blood group B(III): B antigen, agglutinate with blood group A(II) and O(I).

Blood group AB(IV): A and B antigen, agglutinate with all blood groups. No antibody.

Blood group name is determined by the antigen present on RBC, but the patient has an opposite antibody. So whenever, the antibody corresponds to the antigen, there is agglutination. Since O does not have any antigen, no agglutination can occur.

194.

Pharmacological effects of anti- depressants are based upon blocking (inhibiting)  the   enzyme   that   acts  as  a catalyst for the breakdown of biogenic amines noradrenalin and serotonin in the mitochondria of cephalic  neurons. What enzyme takes part in this process?

Explanation

image

Norepinephrine (noradrenaline), epinephrine (adrenaline) and dopamine are catecholamines produced in chromaffin cells of adrenal medulla from tyrosine. The catecholamines are inactivated by oxidative deamination catalyzed by monoamine oxidase (MAO) and by O-methylation carried out by Catechol-O-methyltransferase. The metabolic products of these reactions are excreted in the urine as vanillymandelic acid from epinephrine and norepinephrine; and homovanillic acid from dopamine.

195. An  oncological  patient was administered   methotrexate.  With  the  lapse  of time  the  target  cells of  the  tumour  lost sensitivity to this preparation. We can observe  changes  in  the  gene  expression of the following enzyme:

Explanation

IMG_9914

Methotrexate is structurally related to folic acid and acts as an antagonist of that vitamin by inhibiting dihydrofolate reductase (in humans), which is the enzyme that converts folic acid to its active coenzyme form, tetrahydrofolic acid. Trimethoprim and pyrimethamine inhibit the same enzyme but in bacteria and protozoa respectively. This decreases dTMP, needed for DNA synthesis.

196.

A  patient with  a  hypertensive  crisis was admitted to the cardiological department. He was given an intravenous injection of an antihypertensive drug - alkali-earth metal salt. What drug was injected?

Explanation

Allochol and cholenzyme are agents of biliary acids and bile (cholesecretics – induce bile secretion). Cholosas is a plant agent (cholesecretics – induce bile secretion). Nicodinum is a synthetic agent (cholesecretics – induce bile secretion). They all stimulate bile formation. Magnesium sulfate is a drug causing gall bladder contraction and relaxation of sphincter of oddi; it promotes bile excretion. It is also a salt laxative acting on all intestine’s secretions. It is a non-absorbable salt that hold water in the intestine by osmosis and distend the bowel, increasing intestinal activity and producing defecation.

197.

An  injured  person  was delivered  to the  hospital  with a penetrating wound  in the  left lateral  region  of abdomen. What part  of the  large  intestine is most  likely damaged?

Explanation

imageimage

Anterolateral abdominal wall has 9 regions and 4 quadrants (RUQ, LUQ, RLQ, LLQ)

·        Right lateral abdominal region: Ascending colon (colon ascendens), right kidney, right ureter and loops of small intestine.

·        Umbilical region: Transverse colon (colon transversum), head of pancreas, duodenum (except superior part)

·        Left lateral abdominal region: Descending colon (colon descendens), left kidney, left ureter and loops of small intestine.

·        Left inguinal region: Sigmoid colon (colon sidmoideum), left ureter, left external iliac artery of artery and vein.

·        Right Inguinal region: Caecum, vermiform appendix, right ureter

198.

After  a road  accident  a  driver  was delivered to the hospital  with an injury of the  medial  epicondyle  of humerus.  What nerve might be damaged in this case?

Explanation

krushkrok No10 (2012)        

The Ulnar nerve arises from the medial cord of the brachial plexus. It runs along the medial bicipital groove, and proceeds to the ulnar groove situated on the posterior surface of the medial epicondyle of humerus. There the nerve runs covered by fascia and skin only.

Musculocutaneous nerve arises from the lateral cord then traverses the coracobrachialis and appears in between the biceps brachii and the brachialis muscles.

Radial nerve (nervus radialis) arises from the posterior cord of brachial plexus. It passes the radial canal along with deep artery of arm. The nerve quits the canal via its inferior opening (in between the brachialis and the brachioradialis muscle) that leads to the cubital fossa; here at the head of radius, the nerve splits into the superficial and deep branches.

199.

A man with a stab wound in the region of the quadrilateral foramen  consulted a doctor  about  it. Examination revealed that  the  injured  couldn’t abduct  his arm from the  body. What  nerve  is most likely damaged?

Explanation

krushkrok No28 (2013)

The axillary nerve (nervus axillaris) from brachial plexus, is the greatest branch of the short branches of brachial plexus. It arises from the posterior cord and proceeds to the quadrangular/quadrilateral foramen. It supplies the deltoid and teres minor muscles. The axillary nerve and posterior circumflex humeral artery pass through the quadrangular space. Borders of the quadrangular space:

·        Superior: Teres minor

·        Inferior: Teres major

·        Medial: Long head of triceps

·        Lateral: humerus

200.

Examination of the anterior abdominal  wall  of  a  pregnant woman  revealed a  tumour-like  formation  that   arose   on the  spot  of a tumour that  was removed two years ago. The neoplasm  was well- defined,  dense, 2х1 cm large. Histological examination revealed that the tumour was composed  of differentiated connective tissue with prevailing  collagen fibres. What tumour might be suspected?

Explanation

     Desmoid fibroma is a benign connective tissue tumor. It a kind of dense fibroma and characterized by infiltrating growth and relapses. It is composed of banal, “tame-looking” fibroblasts that do not metastasize. More often it is located on the anterior abdominal wall.