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Question 1 of 200

1. A patient with hypochromic anemia has splitting hair and loss of hair, increased nail brittling and taste alteration. What is the mechanism of the development of these symptoms?

Explanation

Microscopically, iron deficiency anemia is characterized by hypochromia (red cells are pale) and smaller than nomal (microcytic); chlorosis (pale-greenish colouration of skin). There is alopecia, koilonychias, atrophies of the tongue and gastric mucosa (atrophic glossitis and atrophic gastritis). Plummer-Vinson triad: hypochromic microcytic anemia, atrophic glossitis and esophageal webs.

B12 –folic acid deficiency: megaloblastic macrocytic anemia

2.

A 27-year-old woman has dropped penicillin containing eye drops. In a few minutes there appeared feeling of itching, burning of the skin, lips and eyelids edema, whistling cough, decrease of BP. What immunoglobulins take part in the development of this allergic reaction?

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)

Type I Hypersensitivity reaction (HSR); anaphylactic and atopic: free antigen cross-links IgE on presensitized (i.e. exposed to the antigen before) mast cells and basophils, triggering immediate release of vasoactive amines that act at postcapillary venules (i.e. histamine). Reaction develops rapidly after antigen exposure because of preformed antibody from first exposure. IgE is the main immunoglobulin involved in type I HSR. Type I: uses IgE and IgG4

3. A person felt thirsty after staying under the conditions of hot weather for a long time. Signals of what receptors caused it first of all?

Explanation

          Hypothalamus regulates water content of the body by two mechanisms:

·        Thirst mechanism

·        Antidiuretic hormone (ADH) mechanism

      Thirst center is in the lateral nucleus of hypothalamus. There are some osmoreceptors in the areas adjacent to thirst center. When the extracellular fluid volume decreases, the osmolality of extracellular fluid (ECF) is increased. If the osmolarity increases by 1 – 2%, the osmoreceptors are stimulated. Osmoreceptors in turn activate the thirst center and thirst sensation is initiated. Now the person feels thirsty and drinks water.

4.

Slime, blood and protozoa 30-200 microns long have been revealed in a man’s feces. The body is covered with cilias and has correct oval form with a little bit narrowed anterior and wide round shaped posterior end. At the anterior end a mouth is visible. In cytoplasm there are two nuclei and two short vacuoles. What are the described features typical for?

Explanation

         Balantidium coli causes balantidiasis. It is the only ciliated protozoan that causes human disease i.e. diarrhea. Domestic animals, especially pigs are the main reservoir for the organism and humans are infected after ingesting the cysts in food or water contaminated with animal or human faeces. Diagnosis is made by finding large ciliated trophozoites or large cysts with a characteristic V-shaped nucleus in the stool. The trophozoites excyst in the small intestine, travel to the colon (large intestine) and by burrowing into the wall cause an ulcer similar to that of Entamoeba histolytica.

5. A child has got galactosemia. Concentration of glucose in blood has not considerably changed. Deficiency of what enzyme caused this illness?

Explanation

Classic galactossemia: absence of galactose 1-phosphate uridyltransferase. It is an autosomal  recessive disorder. It causes galactosemia and galactosuria, vomiting, diarrhea and jaundice. There is accumulation of galactose 1-phosphate and galacitol in nerve, lens, liver and kidney tissue causes liver damage, severe mental retardation and cataracts.

Also galactokinase deficiency can cause elevation of galactose in blood (galactosemia) and urine (galactosuria). This is a rare autosomal recessive disorder. It causes galacitol accumulation if galactose is present in diet.

6.

Synthesis of phospholipids is disturbed as a result fatty infiltration of liver. Indicate which of the following substances can enhance the process of methylation during phospholipids synthesis?

Explanation

Hepatic steatosis can occur when humans are deprived of choline.

Choline + Phosphatidic acid → Phosphatidylcholine (lecithin, PC). In the liver PC can also be synthesized from phosphatidylserine (PS) and phosphatidylethanolamine (PE), when free choline levels are low, because it exports significant amounts of PC in bile and as a component of serum lipoproteins (needed for fat metabolism)

PS → PE →→→ PC. 3 methylation reactions between PE and PC. S-adenosylmethionine is the methyl group donor. If choline, phosphatidylcholine or methionine is deficient, there will be abnormal phospholipid synthesis, oxidative damage caused by mitochondrial dysfunction, lipoprotein secretion (remember, if VLDL cannot be secreted it will be accumulated & cause fatty liver degeneration as seen in hepatic steatosis). PC is also a major lipid component of lung surfactant.

7.

An individual is characterized by rounded face, broad forehead, a mongolian type of eyelid fold, flattened nasal bridge, permanently open mouth, projecting lower lip, protruding tongue, short neck, flat hands, and stubby fingers. What diagnosis can be put to the patient? 

Explanation

All these manifestations listed in the question characterize Down's syndrome.

Chromosomal disorders: trisomy 21 (down’s syndrome); trisomy 18 (edward’s syndrome); trisomy 13 (patau’s syndrome); monosomy X (turner’s syndrome-XO); trisomy X (XXX);

normal female (XX); normal male (XY)

8.

A patient visited a dentist with complaints of redness and edema of his mouth mucous membrane in a month after dental prosthesis. The patient was diagnosed with allergic stomatitis. What type of allergic reaction by Gell and Cumbs underlies this disease? 

Explanation

Delayed - a month

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.

9.

A patient suffering from thrombophlebitis of the deep crural veins suddenly died. Autopsy has shown freely lying red friable masses with dim crimped surface in the trunk and bifurcation of the pulmonary artery. What pathologic process was revealed by morbid anatomist? 

Explanation

Pulmonary embolism is the most common and fatal form of venous thromboembolism in which there is occlusion of pulmonary arterial tree by thromboemboli. Pulmonary emboli are more common in hospitalized or bedridden patients. The majority of emboli arise from the deep veins of the lower extremities; most of the fatal ones arise from the ileofemoral veins. Consequences of thromboembolism include pulmonary infarction in which pyramidal segments (or ‘triangular’ segments) of hemorrhagic infarction are seen at the periphery of the lung. Detachment of thrombi from the thrombophlebitis site in the lower limbs produces a thromboembolus that flows through venous drainage into the large veins draining into the right side of the heart and then to the pulmonary circulation where they embolize.

10. Decreased blood supply to the organs causes hypoxia that activates fibroblasts function. Volume of what elements is increased in this case?

Explanation

         Fibroblast is the principal cell of connective tissue. Fibroblasts are responsible for the synthesis of collagen, elastic and reticular fibers, and the complex carbohydrates of the ground substance. Ground substance occupies the space between the cells and fibers (intercellular space). Research suggests that a single fibroblast is capable of producing all of the extracellular matrix components.

11. RNA-polymerase B(II) is blocked due to amanitine poisoning (poison of death-cup). It disturbs:

Explanation

        The process of transcription of a typical gene can be divided into 3 phases: initiation, elongation and termination. The process of transcription begins with the binding of the RNA polymerase holoenzyme to a region of the DNA known as the promoter. RNA polymerase is a multisubunit enzyme that recognizes a nucleotide sequence (the promoter region) at the beginning of a length of DNA that is to be transcribed. RNA polymerase synthesizes mRNA. It makes a complementary RNA copy of the DNA template strand and then recognizes the end of the DNA sequence to be transcribed (the termination region).

12.

Secretion of what gastrointestinal hormones will be primarily decreased as a result of duodenum removal?

Explanation

          Secretin is produced by S cells of mucous membrane in duodenum and jejunum. Secretin stimulates the secretion of watery juice which is rich in bicarbonate ion and high in volume; increase bile secretion and decrease gastric acid secretion.

Cholecystokinin (also called cholecystokinin-pancreozymin) is secreted by I cells in duodenal and jejuna mucosa. It stimulates the secretion of pancreatic juice which is rich in enzyme and low in volume; increase gallbladder contraction; increase sphincter of oddi relaxation; decrease gastric emptying. Therefore, removal of duodenum will decrease cholecystokinin and secretin secretion.

13.

It is planned to use the territory of an old cattle burial ground (which is not used for more than 50 years) for building houses. But ground analysis revealed presence of the pathogen of a very dangerous illness. Which of the indicated microorganisms is likely to remain in the ground for such a long time?

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.

14.

From the nasopharynx of a 5-year-old child it was excreted a microorganism which is identical to Corynebacterium diphtheriae dose according to morphological and biochemical signs. But this microorganism does not produce exotoxin. As a result of what process can this microorganism become toxigenic?

Explanation

15. A   patient   with   encephalopathy was admitted to the neurological in-patient department. There was revealed a correlation between increasing of encephalopathy and substances absorbed by the bloodstream from the intestines. What substances that are formed in the intestines can cause endotoxemia?

Explanation

Normally, protein digestion takes place in the stomach and small intestine. When this process is impaired, the  protein goes to the large intestine undigested and the gut microflora degrades/breaks down protein into ammonia, phenols, indoles and amines which have been shown to exert toxic effects in vitro and in animal models. Human studies have shown that colonic protein metabolism via the gut microflora is responsive to dietary protein as faecal ammonia and urinary phenolic compound concentrations increase in response to increased intake of protein rich foods. 

16.

A 50-year-old man has felt vague abdominal discomfort within past 4 months. Physical examination revealed no lymphadenopathy, and no abdominal masses or organomegaly at palpation. Bowel sounds are heard. An abdominal CT scan shows a 20 cm retroperitoneal soft tissue mass obscuring the left psoas muscle. A stool specimen tested for occult blood is negative. Which of the following neoplasms is this man most likely to have?

Explanation

Lipoma is a benign tumor of fatty tissue. It is the most frequent soft tissue tumor, arising in subcutaneous regions at any site but most commonly on the back, shoulder and neck. It may develop in every site where there is fat tissue. Lipomas are encapsulated, usually small yellow node with distinct (clear) borders.

 

17. A patient has undergone an amputation of lower extremity. Some time later painful nodules appeared in a stump. Amputatious neuromas were found out at the microscopic examination. To what pathological processes do those formations relate?

Explanation

18.

During the fetal period of the development in the vascular system of the fetus a large arterial (Botallo’s) duct is functioning which converts into lig.arteriosum after birth. What anatomical formations does this duct connect?

Explanation

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.

19. A 22-year-old patient was admitted to the hospital with complaints of heavy nasal breathing. During the examination of her nasal cavity the doctors found thickened mucous membrane, a lot of mucus and nodular infiltrates without erosions in the nose. The nasal rhinoscleroma was diagnosed. The biopsy was taken. What typical morphological changes may be found?

Explanation

Microscopic examination of specific granulomas:

* In Rhinoscleroma of nose, the granuloma (scleroma) consists of plasma cells, epitheloid cells, lymphocytes and hyaline sphere. Large macrophages with light cytoplasm containing klebsiella rhinoscleromatis (Mikulicz’s cells), sclerosis and hyalinosis takes place.

* In TB, the granuloma is reffered to as a tubercle and is classically characterized by the presence of central necrosis surrounded by epitheloid cells, lymphocytes, plasma cells and giant langhance cells. In contrast, caseous necrosis is rare in other granulomatous diseases.

* The syphilis granuloma is calle Gumma. Gumma consist of a central area of fibrinoid or caseous necrosis surrounded by mononuclear inflammatory cells, mostly plasma cells, lymphocytes, epitheloid cells and seldom-giant langhance cells. Around gumma forms the granulation tissue and endovasculitis.

* In Tuberculoid Leprosy, the epidermis contains confluent granulomas composed of macrophages, plasma cells and leprous Virchow’s cells – Leprous Virchow’s cells (or Leprous cells) refer to large foamy macrophages within fatty vacuoles containing leprous mycobacterium.

 

20. Intake of oral contraceptives containing sex hormones inhibits secretion of the hypophysiae hormones. Secretion of which of the indicated hormones is inhibited while taking oral contraceptives with sex hormones?

Explanation

     Follicle stimulating hormone and the luteinizing hormone are together called gonadotropic hormones or gonadotropins because of their action on gonads. Products containing a combination of an estrogen and a progestin are the most common type of oral contraceptives. The estrogen provides a negative feedback on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) by the pituitary gland, thus preventing ovulation. The progestin also inhibits LH release and thickens the cervical mucus, thus hampering the transport of sperm. Oral contraceptives are the drugs taken orally (by mouth) to prevent pregnancy.

21.

A 60-year-old patient was admitted to the surgical department because of infection caused by blue pus bacillus (Pseudomonas aeruginosa) which is sensitive to penicillin antibiotics. Indicate which of the given penicillins has marked activity to the Pseudomonas aeruginosa?

Explanation

        Antipseudomonas penicillins: carbenicillin, ticarcillin, piperacillin – these drugs have activity against several gram negative rods, including Pseudomonas, enterobacter and in some cases Klebsiella species. Carbenicillin-disodium is acid-stable and can be administered orally.

22.

A 45-year-old woman suffers from seasonal allergic rhinitis caused by the ambrosia blossoming. What medicine from the stabilizer of the adipose cells group can be used for prevention of this disease?

Explanation

     Ketotifen and cromolyn sodium are membrane stabilizers. Ketotifen stabilize basophils membranes and possesses antihistamine (antiallergic) and sedative effects.

23. A young man felt acute pain in the back during active drawing up on the horizontal bar. Objectively: pain while moving upper extremity, reduced pronation and adduction functions. Sprain of what muscle can be observed here?

Explanation

        Latissimus dorsi is a superficial muscle of the back. The latissimus dorsi is a broad and flat muscle which envelopes the lower portion of the back. The upper part of the latissimus dorsi is covered by the trapezius muscle. The latissimus dorsi pulls the arm backward and medially, rotating the shoulder towards the midline; lowers the raised arm. When the arm is fixed, it pulls the trunk towards the arms (as in exercises on the pull up bar or in crawling).

24. A 52-year-old patient has the following diagnosis: systemic amebiasis with involvement of intestines, liver, lungs. What drug should be prescribed?

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.

25.

A 38-year-old man who poisoned himself with mercury dichloride was taken to the admission room in grave condition. What antidote should be immediately introduced?

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.

 

26. Children often have heavy nasal breathing resulting from excessive development of lymphoid tissue of pharyngeal mucous membrane. What tonsils growth may cause this effect?

Explanation

       The pharyngeal tonsil (tonsilla pharyngea) is localized in the nasopharynx. It is an aggregation of the lymphoid tissue on the border of the vault and the posterior wall, it is visible through the fauces opening. The tonsil is well developed in children. Excessive growth of the tonsil may result in labored nasal breathing, in such cases removal of the tonsil is indicated.

27. The alternate usage of dichlotiazide, etacrin acid and lasex did not influence diuretically upon the patient with marked peripheral edemata. The aldosterone rate in the blood is increased. Indicate which medicine should be prescribed:

Explanation

K+ sparing diuretics:

  - aldosterone antagonist: spironolactone, eplerenone

  - inhibit Na+ reabsorption: triamterene

The answer is Spironolactone because after the administration of other diuretics, 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.

28.

A 46-year-old man complains of difficulties with nasal breathing. Mikulicz’s cells, accumulation of epithelioid cells, plasmocytes, lymphocytes, hyaline balls were discovered in the biopsy material of the thickened nasal mucosa. What is the most likely diagnosis?

Explanation

Microscopic examination of specific granulomas:

* In Rhinoscleroma of nose, the granuloma (scleroma) consists of plasma cells, epitheloid cells, lymphocytes and hyaline sphere. Large macrophages with light cytoplasm containing klebsiella rhinoscleromatis (Mikulicz’s cells), sclerosis and hyalinosis takes place.

* In TB, the granuloma is reffered to as a tubercle and is classically characterized by the presence of central necrosis surrounded by epitheloid cells, lymphocytes, plasma cells and giant langhance cells. In contrast, caseous necrosis is rare in other granulomatous diseases.

* The syphilis granuloma is calle Gumma. Gumma consist of a central area of fibrinoid or caseous necrosis surrounded by mononuclear inflammatory cells, mostly plasma cells, lymphocytes, epitheloid cells and seldom-giant langhance cells. Around gumma forms the granulation tissue and endovasculitis.

* In Tuberculoid Leprosy, the epidermis contains confluent granulomas composed of macrophages, plasma cells and leprous Virchow’s cells – Leprous Virchow’s cells (or Leprous cells) refer to large foamy macrophages within fatty vacuoles containing leprous mycobacterium.

 

29. A 56-year-old patient complaining of thirst and frequent urination was diagnosed with diabetes mellitus. Butamin was prescribed. How does the medicine act?

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.

Butamin (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.

30. A man who was bitten by the unknown dog applied to the surgeon. Wide ragged wounds were localized on the face. What curative-prophylactic aid should be given to prevent rabies?

Explanation

As the name implies, anti-rabies vaccine is used to prevent (prophylaxis) rabies. It can also be used for treatment (curative). Rabies is a viral disease of animals and humans can be infected by animal’s bite (most common – Dog). A dog can be immunized against the disease.

 

31.

A patient with clinical signs of immunodeficiency has no changes of the number and functional activity of T- and B- lymphocytes. Defect with dysfunction of antigen-presentation to the immunocompetent cells was found during examination on the molecule level. Defect of what cells is the most probable?

Explanation

           Antigen presenting cells are the special type of cells in the body, which induce the release of antigenic materials from invading organisms and later present these materials to the helper T cells. Types of antigen presenting cells are macrophages (monocytes); dendritic cells and B lymphocytes. Among these cells, macrophages are the major antigen presenting cells. Macrophages are the tissue form of monocytes (monocytes are in blood; when monocytes get out of blood circulation into tissue they become macrophages).

32. A 38-year-old woman was admitted to the admission-diagnostic department with uterine bleeding. What are the most likely changes of blood?

Explanation

Hematocrit is the percentage of cells present in plasma.  Normal hematocrit is approximately 45%. After uterine bleeding, her circulating blood volume is reduced as a result of the bleeding which result in a decrease or reduction in the hematocrit rate.

33.

A 60-year-old patient has reduced perception of high-frequency sounds. What structures’ disorder of auditory analyzer caused these changes?

Explanation

Two membranes divide the spiral canal of cochlea into 3 compartments – vestibular and basilar membrane. Along the basilar membrane are 20,000-30,000 tiny fibers called basilar fibers. Each fiber has different size and shape. Fibers near the oval window (base) are short and stiff (narrowest), while approaching towards helicotrema (apex), the basilar fibers gradually become longer and soft (widest). The motion of the basilar membrane is generally described as a travelling wave. The parameters of the membrane (stiffness, narrow, wide) at a given point along its length determine its characteristic frequency at which it is most sensitive to sound vibrations. High frequency sounds localize near the base of the cochlea (near the round and oval windows), while low frequency sounds localize near the apex (helicotrema); and the middle frequency sounds – middle part of helix.

 

34.

The effect of electric current on the excitable cell caused depolarization of its membrane. Movement of what ions through the membrane caused depolarisation?

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 excitable 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.

35.

Live vaccine was injected into the human body. Increasing activity of what connective tissue cells can be expected?

Explanation

Live spore vaccine (STI) is used for vaccination against anthrax. STI live vaccine. Vaccines stimulates the production of antibodies. Now, when B-lymphocytes are exposed to this weakened antigens (vaccine), they differentiate into plasma cells (plasmocytes) which then produce specific antibodies to this antigen.
36.

When a patient with traumatic impairment of the brain was examined, it was discovered that he had stopped to distinguish displacement of an object on the skin. What part of the brain was damaged?

Explanation

Postcentral gyrus (i.e. part of parietal lobe immediately posterior to central sulcus) is concerned with sensory information (touch).

Precentral gyrus (i.e. part of frontal lobe immediately anterior to central sulcus) is concerned with motor information. Occipital lobe: visual cortex. Cerebellum: coordination of movement and postural adjustment. Temporal lobe: superior temporal gyrus – located in temporal lobe immediately below sylvian fissure concerned with auditory stimuli. 

37.

In the blood of a 26-year-old man 18% of erythrocytes of the spherical, ball-shaped, flat and spinous shape have been revealed. Other erythrocytes were in form of the concavo-concave disks. How is this phenomenon called?

Explanation

    Poikilocytosis is the presence of abnormally shaped erythrocytes (poikilocytes); they could be spherical in shape (spherocytes), oval or cigar shaped (elliptocytes), with slit-like rectangular or mouthlike area (stomatocytes) etc. The presence/absence of poikilocytosis indicated by the erythrocytic index MCHC – mean corpuscular hemoglobin concentration: the average concentration of hemoglobin in a given volume of packed red blood cells, expressed in percentage (%).

MCHC = [Hb (g/L) ÷  Hematocrit] X 100.

Norm: 32.4 – 34.8%

The percentage of poikilocytes (18%) is relatively low and therefore can be considered physiological. Moreso, no pathological condition is recorded in the patient.

Anisocytosis is the presence of differently sized cells e.g. normocytes, microcytes and macrocytes.

38.

A 10-year-old girl often experiences acute respiratory infections with multiple punctate haemorrages in the places of clothes friction. Hypovitaminosis of what vitamin has the girl?

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

39.

Different functional groups can be presented in the structure of L-amino acid’s radicals. Identify the group that is able to form ester bond:

Explanation

40.

Moving of the daughter chromatids to the poles of the cell is observed in the mitotically dividing cell. At what stage of the mitotic cycle is this cell?

Explanation

41.

During examination of a patient, there was found a neoplasm in the white substance of cerebral hemispheres with localization in the knee and frontal part of posterior crus of internal capsule. Fibres of what conductive tract of the brain will be disrupted?

Explanation

The pyramidal fasciculus is subdivided into the corticonuclear/corticobulbar fibers and the corticospinal fibers. The fiber of the pyramidal fasciculus passes through the genu and the anterior portion of the internal capsule and descends to the brainstem and the spinal cord. The corticonuclear tract passes through the genu of the internal capsule.  The genu is situated between the anterior and posterior limbs. Lesion in genu causes alteration in motor activities in opposite side due to damage of corticonuclear/corticobulbar fibers.

42.

A patient with diabetes mellitus has been delivered in hospital in the state of unconsciousness. Arterial pressure is low. The patient has acidosis. Point substances, which accumulation in the blood results in these manifestations:

Explanation

When the rate of formation of ketone bodies is greater than the rate of their use, their levels begin to rise in blood (ketonemia) and eventually in the urine (ketonuria). These two conditions are seen most often in cases of uncontrolled type I diabetes mellitus. In such individuals, high fatty acid degradation produces excessive amounts of acetyl CoA. It also depletes the NAD+ pool and increases the NADH pool, which slows the citric acid cycle. This forces the excess acetyl CoA into the ketone body pathway. An elevation of the ketone body concentration in  the blood results in metabolic acidosis.
43. A person has steady HR not exceeding 40 bpm. What is the pacemaker of this person’s heart rhythm?

Explanation

The sinoatrial (SA) node is a small strip of modified cardiac muscle, situated in the superior part of lateral wall of right atrium, just below the opening of superior vena cava. The fibers of this node do not have contractile elements. SA node is called the pacemaker because the rate of production of impulse (rhythmicity) is higher in SA node than in other parts. The rate is 60-100/min and higher during tachycardia when stimulated by sympathetic effects. Atrioventricular (AV) node is 40-60/min.

44.

A doctor administered Allopurinol to a 26-year-old young man with the symptoms of gout. What pharmacological action of Allopurinol ensures therapeutical effect?

Explanation

Allopurinol is a purine analog. It reduces the production of uric acid by competitively inhibiting the last two steps in uric acid biosynthesis that are catalyzed by xanthine oxidase. NOTE: Uric acid is less water soluble than its precursors. When xanthine oxidase is inhibited, the circulating purine derivatives (xanthine & hypoxanthine) are more soluble and therefore are less likely to precipitate. 
45.

A patient who came to the doctor because of his infertility was administered to make tests for toxoplasmosis and chronic gonorrhoea. Which reaction should be performed to reveal latent toxoplasmosis and chronic gonorrhoea of the patient?

Explanation

46.

Under some diseases it is observed aldosteronism accompanied by hypertension and edema due to sodium retention in the organism. What organ of the internal secretion is affected under aldosteronism?

Explanation

Aldosterone produced in adrenal cortex (zona glomerulosa): causes increased sodium (Na+) reabsorption; increased potassium and hydrogen ions (↑K+, H+) excretion. They increase sodium (↑Na+) channel and Na+ /K+-pump insertion in principal cells of collecting duct; enhances K+ and H+ excretion by way of principal cell K+ channels and α-intercalated cell H+ ATPases of collecting duct. Therefore, increase in aldosterone → ↑ K+ in urine (excretion) and ↓ Na+ in urine (↑ reabsorption); And decreased aldosterone → ↓ K+ excretion (↓K+ in urine) and ↓ Na+  reabsorption (i.e. ↑Na+ in urine); same effects on sweats glands too.

47. Patient had been taking glucocorticoids for a long time. When the preparation was withdrawn he developed the symptoms of disease aggravation, decreased blood pressure and weakness. What is the reason of this condition?

Explanation

One of the major setbacks related to continuous, long term steroid (cortisol, prednisolone) treatments are symptoms due to changes in the balance of normal hormone secretion. This typically results from taking doses greater than our body’s natural production. Once we begin to decrease or discontinue the dose, however, withdrawal symptoms may occur. Thus, steroids are typically given for the shortest time possible. Short-term use does not induce steroid withdrawal syndrome. In general, the longer you are on this steroid, the longer it is going to take your body to readjust to functioning without it. If you are on it for longer than 2 weeks, it can affect your adrenal glands ability to produce cortisol leading to adrenal insufficiency.

48. A patient has tissue ischemia below the knee joint accompanied with intermittent claudication. What artery occlusion should be suspected?

Explanation

The popliteal artery is a direct continuation of the femoral artery. It occupies the popliteal fossa together with the popliteal vein and supplies all structures below the knee joint. Upon reaching the leg region, the artery enters the cruropopliteal canal and gives off its two terminal branches – the anterior and posterior tibial arteries. Therefore, a tissue ischemia below the knee joint must be as a result of occlusion of the popliteal artery.

49.

An experiment proved that UV-radiated cells of patients with xeroderma pigmentosum restore the native DNA structure slower than cells of healthy individuals as a result of reparation enzyme defection. What enzyme helps this process?

Explanation

Exposure of a cell to ultraviolet (UV) light can result in the covalent joining of two adjacent pyrimidines (usually thymine), producing a dimer. These thymine dimers prevent DNA polymerase from replicating the DNA strand beyond the site of dimer formation. First, a UV-specific endonuclease recognizes the dimer an cleaves the damaged strand on both the 5’-side and 3’-side of the dimer. Pyrimidine dimers can be formed in the skin cells of humans exposed to unfiltered sunlight. In the rare genetic disease Xeroderma pigmentosum, the cells cannot repair the damaged DNA because UV-specific endonuclease is defective, resulting in extensive accumulation of mutations and consequently, skin cancers.

50.

A patient, who suffers from congenital erythropoietic porphyria, has skin photosensitivity. The accumulation of what compound in the skin cells can cause it?

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.

51. A sick man with high temperature and a lot of tiny wounds on the body has been admitted to the hospital. Lice have been found in the folds of his clothing. What disease can be suspected?

Explanation

Epidemic typhus (human body louse) – Rickettsia prowazekii, can remain latent and reactivate months or years in an infected patient, with symptoms similar to or even identical to the original attack of typhus, including a rash that starts centrally and spreads out, sparing palms and soles. This delayed relapse of epidemic typhus – Brill’s disease.

Epidemic typhus - Lice

52. A patient with suspicion on epidemic typhus was admitted to the hospital. Some arachnids and insects have been found in his flat. Which of them may be a carrier of the pathogen of epidemic typhus?

Explanation

Epidemic typhus (human body louse) – Rickettsia prowazekii, can remain latent and reactivate months or years in an infected patient, with symptoms similar to or even identical to the original attack of typhus, including a rash that starts centrally and spreads out, sparing palms and soles. This delayed relapse of epidemic typhus – Brill’s disease.

Epidemic typhus - Lice
53. A businessman came to India from South America. On examination the physician found that the patient was suffering from sleeping-sickness. What was the way of invasion?

Explanation

     The genus Trypanosoma includes 3 major pathogens: Trypanosoma cruzi, Trypanosoma gambiense and Trypanosoma rhodesiense. T. cruzi causes American trypanosomiasis (chagas disease); the reduvid bug (kissing bug or Triatoma) is the vector.

T. gambiense and T. rhodesiense cause sleeping sickness (African trypanosomiasis); the vector for both is the tse-tse fly (Glossina).

54. Patients with bile ducts obstruction suffer from inhibition of blood coagulation, bleedings as a result of low level of vitamin assimilation. What vitamin is in deficiency?

Explanation

Lipid malabsorption resulting in increased lipid (including the fat soluble vitamins A, D, E, K and essential fatty acids – linoleic acid) in the faeces (steatorrhea), can be caused by disturbances in lipid intake or digestion and/or absorption. Lack of vitamin A (vision impairment and poor wound healing); lack of linoleic acid (dermatitis).  Lack of vitamin K leads to impairment in blood coagulation because:

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.

55. Blood analysis of a patient showed signs of HIV infection (human immunodeficiency virus). Which cells does HIV-virus primarily affect?

Explanation

           Human immunodeficiency virus (HIV): diploid genome (2 molecules of RNA). The 3 structural genes(i.e. proteins coded for by the genes) are:

·        env (gp 120 and gp 41): formed from cleavage of gp 160 to form envelope glycoproteins. gp 120 is for attachment to host CD4+ T cell. gp 41 is for fusion and entry.

·        Gag (p24): capsid protein

·        pol: reverse transcriptase, aspartate protease, integrase.

ELISA/Western blot (immunoblot) tests look for antibodies to the viral proteins listed above.

Reverse transcriptase synthesizes dsDNA (ds-double stranded) from genomic RNA (mRNA); dsDNA integrates into host genome. Virus binds CD4 as well as a coreceptor, either CCR5 on macrophages (early infection) or CXCR4 on I cells (late infection).

·        Homozygous CCR5 mutation – immunity

·        Heterozygous CCR5 mutation – slower course.

56. The preventive radioprotector was given to a worker of a nuclear power station. What mechanism from the below mentioned is considered to be the main mechanism of radioprotection?

Explanation

Free radical oxidation products forming in irradiated tissues of the organisms are called radiotoxins. In the pathogenesis of radiation damage lipid radiotoxins (lipid hydroperoxides, epoxides) are considered to be of great significance. Being intermediate and final products of lipid peroxidation, they accumulate in the cell membranes impairing their barrier functions. Antioxidants block hydroxyl radical recombination into hydrogen peroxide, preventing stable organic hydrogen peroxide compounds from occurring. This is one way in which the body can defend itself from indirect radiation interactions on a cellular level, and is one reason why antioxidants have received so much attention recently as radioprotectors and cancer prevention agents.

57. The pulmonalis embolism has suddenly developed in a 40-year-old patient with opened fracture of the hip. Choose the possible kind of embolism:

Explanation

Embolism is occlusion of a vessel by material travelling in the circulation.

* Fat/Adipose embolism: obstruction of arterioles and capillaries by fat globules constitutes fat embolism. It may occur following severe fracture trauma to bones, inflammation of bones and soft tissues, fatty liver

* Thromboembolism: a detached thrombus or part of thrombus which may arise in the arterial or venous circulation.

* Gas embolism: two main forms of gas embolism are air embolism and decompression sickness. Air embolism is usually due to accidental pumping of air into the venous circulation during intravenous (IV) injection or transfusion ( bubble – air escaped).

Tissue embolism: fragments of tissue.

58. A patient’s blood was analyzed and the decreased erythrocyte’s sedimentation rate (ESR) was discovered. What disease from the listed below is accompanied with decreased ESR?

Explanation

Normal erythrocyte sedimentation rate (ESR): men: 2 – 10mm/h

                                                                                                Women: 2 – 15mm/h

Products of inflammation (e.g. fibrinogen) coat RBCs and cause aggregation. The denser RBC aggregates, fall at a faster rate within a pipette tube. Therefore, an increase in fibrinogen (2x increase) should produce a proportional increase in ESR.

40 – 50mm/h is the only option higher than the normal range.

↑ESR: most anemias, infections, inflammation (e.g. temporal arteritis), cancer (e.g. multiple myeloma), pregnancy, autoimmune disorders (e.g. SLE)

↓ESR: sickle cell anemia (altered shape), polycythemia (↑RBCs “dilute” aggregation factors), microcytosis, hypofibrinogenemia

59. A 46-year-old patient has complained of headache, fatigue, thirst, pains in the spine and joints for the last 2 years. Clinically observed disproportional enlargement of hands, feet, nose, superciliary arches. He notes that he needed to buy bigger shoes three times. What is the main reason of such disproportional enlargement of different parts of the body?

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.

60. A mother of a newborn complains of her baby’s constant belching with undigested milk. Which developmental anomaly is it an evidence of?

Explanation

Esophageal atresia results either from spontaneous posterior deviation of the tracheoesophageal septum or from some mechanical factor pushing the dorsal wall of the foregut anteriorly. Atresia of the esophagus prevents normal passage of amniotic fluid into the intestinal tract, resulting in accumulation of excess fluid in the amniotic sac (polyhydramnios). In addition to atresias, the lumen of the esophagus may narrow, producing esophageal stenosis, usually in the lower third. Stenosis may be caused by incomplete recanalization, vascular abnormalities or accidents that compromise blood flow. Occasionally, the esophagus fails to lengthen sufficiently and the stomach is pulled up into the esophageal hiatus through the diaphragm. The result is a congenital hiatal hernia. There is difficulty with feeding; food is regurgitated out of the mouth. Frothing and bubbling around the mouth at birth is seen.

61. During the endoscopy the inflammation of a major papilla of the duodenum and the disturbances of bile secretion were found. In which part of duodenum were the problems found?

Explanation

The sole longitudinal fold on the mucosa of duodenum which lies on the posteromedial wall of the descending part. It appears as the result of evagination of the bile duct running along the wall. The major duodenal papilla lies at the lower end of the longitudinal fold. On the top of the papilla, there is an opening for bile and pancreatic ducts which delivers pancreatic secretion and bile to duodenal lumen.

62. An 18-year-old patient came to the out-patient department with the complaints of bleeding trauma in the vestibule of his nose. On examination: the mechanical injury of the mucous layer of the vestibule without continuation into nasal cavity proper. What is the boundary between the vestibule and nasal cavity proper?

Explanation

The nasal cavity opens with the nostrils to exterior and with choanae to the pharynx. The extended portion of the nasal cavity neighbouring to the nostrils is the limen nasi (nasal limen), the portion respective to the ala area separated from the nasal cavity proper with the major alar cartilage projection called the nasal vestibule. The limen nasi (nasal limen) lining is continuous with facial skin and has longer vibrissae that filter air and sweat and sebaceous glands.

63. A 50-year-old patient was injured on the occipital region of the head. The closed skull trauma was diagnosed. She was taken to the hospital. The medical examination: deregulation of walking and balance, trembling of arms. What part of brain was injured?

Explanation

During cerebellar lesions, there  are disturbances in posture, equilibrium and movements. Disturbances in movements: ataxia, asynergia, asthenia (weak muscle contractions with characteristically rapid onset of muscle fatigue), Dysmetria, Intention tremor, astasia (loss of the capacity for sustained tetanic contractions), nystagmus, rebound phenomenon, dysarthria, adiadochokinesis, atonia (lack or impairment of muscle tone).

64. A patient with complaints of dryness in the mouth, photophobia and vision impairment was admitted to the reception-room. Skin is hyperemic, dry, pupils are dilated, tachycardia. Poisoning with belladonna alkaloids was diagnosed on further examination. What medicine should be prescribed?

Explanation

The manifestations listed in the question are sympathetic effects and a cholinomimetic - cholinergic agonist (a parasympathetic agonist) can reverse these effects.

Proserin (neostigmine) is an indirect acting cholinergic agonist (anticholinesterase). It preserves endogenous acetylcholine which can stimulate a greater number of acetylcholine receptors producing parasympathetic effects that can reverse the sympathetic effects mentioned. 

 

65. Autopsy revealed that right lung is enlarged, solid, there are fibrin layers on the pleura. Lung tissue is light grey color on incision with muddy liquid exudates. What lung disease are these symptoms typical for?

Explanation

66. During the operation on the hip joint of a 5-year-old child her ligament was damaged which caused bleeding.What ligament was damaged?

Explanation

     Obturator artery reaches the thigh region via the obturator canal. The artery supplies the adductors of thigh and the hip joint. The hip joint receives blood from the acetabular branch, which passes within the ligament of head of femur. The obturator artery anastomoses with the inferior hypogastric artery via the pubic branch. 

 

67. On autopsy it was revealed: pia mater of the upper parts of cerebral hemisphere is plethoric, of yellowish-green color, soaked with purulent and fibrose exudate, looks like a cap. What disease is it typical for?

Explanation

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.

68. A 55-year-old patient with continuing ventricular arrhythmias was admitted to the hospital. The patient is taking timolol drops for glaucoma, daily insulin injections for diabetes mellitus, and an ACE inhibitor for hypertension. You have decided to use phenytoin instead of procainamide. What is the reason?

Explanation

Procainamide is the amide derivative of local anesthetic agent named procaine (Novocain). Procaine was also found to have antiarrhythmic activity, but is not suitable clinically due to the rapid hydrolysis and marked CNS effects of it. Procainamide also has the anticholinergic effect. Its adverse effects include skin rash, allergic reactions, blurred vision, tremor etc.

Timolol is a non-selective β-adrenergic antagonist (β-adrenoblocker) – they can be used to treat glaucoma because they decrease intraocular pressure through their dilatory action. But the anticholinergic effect of procainamide will cause a further increase in the intraocular pressure in glaucoma.

Glaucoma is increased intraocular pressure.

Phenytoin is a class Ib antiarrhythmic drug that can be used to treat abnormal heart rhythms.

69. A 35-year-old man under the treatment for pulmonary tuberculosis has acute pain onset of right big toe, swelling, and low-grade fever. The gouty arthritis was diagnosed and high serum uric acid level was found. Which of the following antituberculous drugs are known for causing high uric acid levels?

Explanation

Pyrazinamide is a synthetic, orally effective, bactericidal, antitubercular agent used in combination with Isoniazid, rifampin and ethambutol. It is bactericidal to actively dividing organisms, but the mechanism of its action is unknown. Pyrazinamide must be enzymatically hydrolyzed to pyrazinoic acid, which is the active form of the drug. Its toxicity can produce hyperuricemia and hepatotoxicity. Urate retention may precipitate a gouty attack.

70. A person was selling \\\"homemade pork\\\" sausages at the market. State sanitary inspector suspected falcification of the sausages. What serological immune reaction can identify food substance?

Explanation

Precipitation (precipitin): in this test, the antigen is in solution. The antibody cross-links antigen molecules in variable proportions and aggregates (precipitates) form. Precipitin test can be done in solution or in semisolid medium (agar). This reaction can be made quantitative i.e. antigen or antibody can be measured in terms of micrograms of nitrogen present. It is used primarily in research.

71. A patient with rheumatoid arthritis who had been treated with indomethacin has got signs of gastropathy. What activity of the drug can this complication be connected with?

Explanation

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID), an inhibitor of COX-1 and COX-2. Cyclooxygenase (COX) converts arachidonic acid into the endoperoxide precursors of prostaglandin. COX-1 is present in non-inflammatory cells (normal body tissues); COX-2 is present in lymphocytes, polymorphonuclear cells and other inflammatory cells. Side effects: GI symptoms – bleeding, ulceration and perforation. Because COX-1 is used to produce mediators that help to protect gastric mucosa, whenever COX inhibitors are used they produce this side effects.

72. A 25-year-old woman with red and itchy eczematoid dermatitis visits your office. She had a dental procedure one day earlier with administration of a local anesthetic. There were no other findings, although she indicated that she had a history of allergic reactions. Which of the following drugs is most likely involved?

Explanation

Procainamide is the amide derivative of local anesthetic agent named procaine (Novocain). Procaine was also found to have antiarrhythmic activity, but is not suitable clinically due to the rapid hydrolysis and marked CNS effects of it. Procainamide also has the anticholinergic effect. Its adverse effects include skin rash, allergic reactions, blurred vision, tremor etc.

 

73. In course of metabolic process active forms of oxygen including superoxide anion radical are formed in the human body. By means of what enzyme is this anion inactivated?

Explanation

Active forms of oxygen (reactive oxygen species) are formed continuously as by-products of aerobic metabolism, through reactions with drugs and environmental toxins, or when the level of antioxidants is diminished, all creating the condition of oxidative stress. One of the protective mechanisms by which the cell minimize the toxic potential of these compounds is by enzymes that catalyze antioxidant reactions. The 3 most important enzymes are glutathione peroxidase, catalase and superoxide dismutase. The superoxide dismutase is specific for converting superoxide to hydrogen peroxide which is then neutralized by catalase or glutathione peroxidase.

74. A patient has elbow joint trauma with avulsion of medial epicondyle of humerus. What nerve can be damaged in this trauma?

Explanation

       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.

Dorsal scapular nerve (nervus dorsalis scapulae) runs to the levator scapulae and the rhomboid muscles.

Subscapular nerve (nervus subscapularis) supplies the subscapularis and the teres major muscle.

75. A student is writing a thorough summary of a lecture. Quality of summarizing has considerably worsened when his neighbours started talking. What kind of inhibition in the cerebral cortex caused this effect?

Explanation

The dog is conditioned to salivate at the sight of food and flash of light – that is a conditioned reflex that requires learning, memory and recall of previous experience (likewise the student summarizing). The established conditioned reflexes can be inhibited: externally and internally. External inhibition: disturbing factors like a stranger, sudden noise (the bell in the case of a dog and TALKING in the case of the student) or a strong smell can abolish the conditioned reflex and inhibit salivary secretion. This extra stimulus evokes the animal’s curiosity  and distracts the attention. Internal inhibition can be:

*Extinction of conditioned reflex: failure to reinforce the conditioned reflex by unconditioned stimulus.

*Differential: alteration of conditioned stimulus.

76. While enrolling a child to school Mantu’s test was made to define whether revaccination was needed. The test result is negative. What does this test result mean?

Explanation

Tuberculin (Mantoux) skin test: this test is done by intradermal injection of tuberculoprotein (tuberculin), purified protein derivative (PPD). Type IV hypersensitivity reaction.

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.

77. The donor who didn’t donate the blood for a long time was investigated with IFA method. Anti-HBs antibodies were revealed. What does positive result of IFA in this case mean?

Explanation

Hepatitis serologic markers:

·        Anti-HAV (IgM): IgM antibody to HAV; best test to detect acute hepatitis A

·        Anti-HAV (IgG): IgG antibody indicates prior HAV infection and/or prior vaccination. This antibody protects against reinfection.

·        HBsAg: Antigen found on surface of HBV; indicates hepatitis B infection.

·        Anti-HBs: Antibody to HBsAg; indicates immunity to hepatitis B.

·        HBcAg: Antigen associated with core of HBV.

·        Anti-HBc: Antibody to HBcAg

·        HBeAg: A second different antigenic determinant in the HBV core. HBeAg indicates active viral replication and therefore high transmissibility.

·        Anti-HBc: Antibody to HBeAg; indicates low transmissibility.

Hepatitis A virus (HAV); Hepatitis B surface antigen (HBsAg); Hepatitis B core antigen (HBcAg); Hepatitis B e antigen (HBeAg).

If anti-HBs indicates immunity to hepatitis B, it therefore means that the patient has previous hepatitis B (i.e. has been infected before).

78. Testosterone and it’s analogs increase the mass of skeletal muscles that allows to use them for treatment of dystrophy. Due to interaction of the hormone with what cell substrate is this action caused?

Explanation

Hormone receptors are situated either in cell membrane or cytoplasm or nucleus of the target cells. Receptors of thyroid hormones and steroid hormones (testosterone, estrogen, progesterone, aldosterone) are in the nucleus of the cell. They execute their function by acting on genes in the target cells. Hormone-receptor complex moves towards the DNA and binds with DNA. This increases transcription of mRNA and therefore synthesis of proteins.

79. Inhibition of α-motoneuron of the extensor muscles was noticed after stimulation of α-motoneuron of the flexor muscles during the experiment on the spinal cord. What type of inhibition is this process based upon?

Explanation

Reciprocal inhibition is the inhibition of antagonistic muscles when a group of muscles are activated, an important feature of both flexor and extensor reflexes, as a result of reciprocal innervation. Usually, excitation of  one group of  muscles is associated with the inhibition of another…i.e antagonistic group of muscles on the same side. E.g when a flexor reflex is elicited, the flexor muscles are excited (contracted) and the extensor muscles are inhibited (relaxed) in that side.

80. A patient who has been strictly keeping to a certain diet for 10 days went through examination of respiratory coefficient. It was determined that it was equal 1. What have the patient been keeping to?

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

81. Buffer capacity of a worker’s blood was decreased due to exhausting muscular work. By coming of what acid substance in the blood can this state be explained?

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. Athletes (or 'workers' as used in the question) 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.

Increase lactate in blood can result in lactic acidosis, upsetting the fragile buffer system in the body.

82. Examination of initial molecular structure revealed substitution of the glutamic acid by valine. What inherited pathology is it typical for?

Explanation

Sickle cell hemoglobin (HbS) point mutation causes a single amino acid replacement in β chain of hemoglobin (substitution of glutamic acid with valine). Pathogenesis of sickle cell anemia: low O2, high altitude or acidosis precipitates sickling – modified shape (deoxygenated HbS polymerizes) → anemia and vaso-occlusive disease. Clinical findings include: dizziness, general weakness, fatigue, “crew-cut” on skull X-ray due to marrow expansion from increased erythropoiesis (this is also seen in thalassemia)  etc. Sickle cells are crescent-shaped RBCs.

83. Inflamation is characterised by increased permeability of vessels of microcirculation stream, increase of their hydrodynamic blood pressure. Increasing of the osmotic concentration and dispersity of protein structures is present in the intercellular fluid. What kind of edema will appear in this case?

Explanation

Edema due to increase in hydrostatic pressure – Hydrodynamic

Edema due to decrease in colloid-osmotic (oncotic – protein) pressure – Colloid-osmotic

Edema due to increase in permeability of vessel wall – Membranogenic

Edema due to decrease lymph drainage – Lymphogenic                           

A combination of any of the above mechanisms – Mixed.

84. Increased fragility of vessels, enamel and dentine destruction resulting from scurvy are caused by disorder of collagen maturation. What stage of procollagen modification is disturbed under this avitaminosis?

Explanation

Collagen, most abundant protein in human body; organizes and strengthens extracellular matrix. Collagen contains Gly-X-Y (X and Y are proline or lysine). Glycine(Gly) makes 1/3 of collagen. Oxyproline (hydroxyproline) is a major collagen amino acid which enables it to be regarded as a marker that reflects the catabolism of collagen.

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.

85. Scraps of the mycelium of a fungus, spores, air bubbles and fat drops were discovered on microscopy of the patient’s hair excluded from the infected areas. What fungus disease is characterised by this microscopic picture?

Explanation

Favus is caused by anthropophilic fungus Trychophyton schoenleini which affects glabrous skin and scalp. Favus is a form of tinea capitis in which crusts are seen on the scalp. Typical (scutular) form: the main element is a scutula being a pure fungus culture in the epidermis. Affected hair is lusterless, atrophic, brittle, lifeless, very much like hair of old uncared wigs.

86. On autopsy of the 58-year-old man it was revealed: mitral valve is deformed, thickened, not totally closed. Microscopically: foci of collagen fibers are eosinophilic, have positive fibrin reaction. The most likely it is:

Explanation

          Due to the positive fibrin reaction and eosinophilia of the collagen fibers, it is better to choose fibrinoid swelling since there is no record of any inflammatory reaction or cells. Fibrinoid swelling changes is a stromal vascular proteinous degeneration. The main signs are revealed microscopically: the bands of collagen fibers are homogenous, impregnated with plasma proteins.

87. Hypertrychosis of auricles is caused by a gene that is localized in Y-chromosome. Father has this feature. What is the probability to give birth to a boy with such anomaly?

Explanation

Every male child has the Y-chromosome. A Y-linked disease only affects males and a diseased father will pass it to all (100%) his male children. Male sex chromosome (XY)

88. A 54-year-old man was admitted to the hospital with complaints of pain in the right subcostal region, vomiting with blood. Objectively: enlarged liver, varicose veins in the stomach and esophagus. Dysfunction of what vessel is likely to have taken place?

Explanation

These manifestations points to portal hypertension. Portal hypertension:

Pathogenesis: resistance to intrahepatic blood flow due to intrasinusoidal hypertension. Anastomoses between portal vein (vena porta hepatis) tributaries and the arterial system. Complications: ascites, periumbilical venous collaterals (caput medusa); esophageal varices; congestive splenomegaly; hemorrhoids

↑in blood pressure in portal vein → portal hypertension

89. A 37-year-old man was admitted to the surgical department with the symptoms of acute pancreatitis: vomiting, diarrhea, bradycardia, hypotention, weakness, dehydration of the organism. What medicine should be used first of all?

Explanation

Acute pancreatitis is an autodigestion of pancreas by pancreatic enzymes (proteolytic enzymes). Contrycal (Aprotinin, Gordox)- protease inhibitor. Therefore,it can inhibit the proteolytic enzymes digesting the pancreas.  Contrycal also has antifibrinolytic (antiplasmin) and hemostatic effect.
90. A person has reduced diuresis, hypernatremia, hypokalemia. Hypersecretion of what hormone can cause such changes?

Explanation

Aldosterone produced in adrenal cortex (zona glomerulosa): causes increased sodium (Na+) reabsorption; increased potassium and hydrogen ions (↑K+, H+) excretion. They increase sodium (↑Na+) channel and Na+ /K+-pump insertion in principal cells of collecting duct; enhances K+ and H+ excretion by way of principal cell K+ channels and α-intercalated cell H+ ATPases of collecting duct. Therefore, increase in aldosterone → ↑ K+ in urine (excretion) and ↓ Na+ in urine (↑ reabsorption); And decreased aldosterone → ↓ K+ excretion (↓K+ in urine) and ↓ Na+  reabsorption (i.e. ↑Na+ in urine); same effects on sweats glands too.
91. Microspecimen of red bone marrow contains multiple capillaries through the walls of which mature blood cells penetrate into the bloodstream. What type of capillaries are these?

Explanation

Capillaries are the smallest diameter blood vessels, often smaller than the diameter of an erythrocyte. Based on their morphology, 3 types of capillaries are distinguished: continuous, fenestrated and discontinuous (sinusoidal) capillaries. Sinusoidal capillaries are typically found in the liver, spleen and bone marrow. They are bigger in diameter and more irregularly shaped than other capillaries, the basal lamina underlying the endothelium may be partially or even completely absent.

Fenestrated capillaries are found in endocrine glands and sites of fluid and metabolite absorption such as gallbladder and intestinal tract. Continuous capillaries are typically found in muscle, lung and the CNS.

92. A 57-year-old patient was admitted to the gastroenterological department with suspicion of Zollinger-Ellison syndrome because of rapid increase of gastrin level in the blood serum. What is the most probable disorder of the secretory function of stomach?

Explanation

Gastrinoma (Zollinger-Ellison syndrome; G-cell tumors): it is a malignant tumor (60 – 90% of cases) that secretes excess gastrin, producing hyperacidity. Parietal cell mass is increased because of hyperplasia from excessive gastrin production. The majority is located in the duodenum (60% of cases) and less commonly in the pancreatic Islet cells (30% of cases). It is characterized by acid hypersecretion (hyperacidity hypersecretion) with diarrhea; epigastric pain with weight loss; maldigestion of food; peptic ulceration; heartburn from gastroesophageal reflux disease (GERD).

93. For a long time a 49-year-old woman had suffered from glomerulonephritis which caused death. The autopsy revealed that the size of her kidneys was 7 х 3 х 2,5 cm, weight 65,0 g, they were dense and small-grained. Microscopically: fibrinogenous inflammation of serous and mucous membranes, dystrophic changes of parenchymatous organs, brain edema. What complication can cause such changes of serous membranes and inner organs?

Explanation

Uremia is not a single event, but rather a syndrome (a constellation of symptoms) that develops in an individual who has end-stage renal disease. Because the kidney is pivotal in maintaining water, acid-base and electrolyte balance and in removing toxic waste products, the symptoms of uremia are widespread and affect all the organs and tissues of the body. Common symptoms include uremic encephalopathy, hypertension, osteodystrophy with CNS changes, including confusion and psychosis characterizing end stages of renal disease.

94. Upper neck node of sympathetic trunk was removed from the rabbit on experiment. Reddening and increased temperature of the skin of head is observed. What disorder of peripheral circulation of the blood has developed?

Explanation

·        Neuroparalytic arterial hyperemia is caused by damage or blockage of α-adrenoreceptors (sympathetic nervous system). It is characterized by reduction or absence (paralysis) of the sympathetic nervous system effects on the walls of the arteries and arterioles.

·        Neurotonic arterial hyperemia is caused by activation of parasympathetic nervous system; irritation of vascular dilators part of vascular center (CNS) or inhibition of vascular – constrictor part of this center (vasomotor center of CNS); M-cholinoreceptors; H2-histaminereceptors. It is characterized by predominance of the parasympathetic nervous system effects on arterial vascular walls.

 

95. A tissue sample of benign tumor was studied under the electron microscope. A lot of small (15-20 nm) spherical bodies, consisting of 2 unequal subunits were detected. These are:

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.

96. A woman who was infected with toxoplasmosis during the pregnancy has born a child with multiple congenital defects.This is a result of:

Explanation

Intoxication with drugs leads to:

·        Disturbances in organs and systems functions: neurotoxic, hepatotoxic, nephrotoxic, hematotoxic, ulcerogenous – ulcers formation in GIT.

·        Teratogenic: ability to cause fetal malformation (in the first trimester of pregnancy i.e. till 12 weeks.

·        Embryo and fetotoxic: ability to make a toxic influence on embryo and fetus correspondingly, causing disturbance down to death (after 12 weeks).

·        Mutagenic: ability to impact on a genetic level causing mutations in several generations.

·        Blastogenic: ability to cause neoplasms both benign and malignant (carcinogenic).

 multiple congenital defects - fetal malformations.

97. A considerable increase of activity of МВ-forms of CPK (creatinephosphokinase) and LDH-1 was revealed on the examination of patient’s blood. What is the most likely pathology?

Explanation

98. An isolated muscle of a frog is rhythmically irritated with electric impulses. Every next impulse is in a period of relaxation from the previous contraction. What contraction of the muscle occurs?

Explanation

Tetanus is defined as the sustained contraction of muscle due to repeated stimuli with high frequency. When the multiple stimuli are applied at a higher frequency in such a way that the successive stimuli fall during contraction period (period of shortening) of previous twitch, the muscle remains in state of tetanus. While increasing the frequency, fusion of contractions increases every time and finally complete tetanus occurs. Holotetanus – complete tetanus.

When the frequency of stimuli is not sufficient to cause tetanus, the fusion of contractions is not complete and then we have – incomplete/partial/waved tetanus. This occurs (i.e. the next stimuli occurs) during the period of relaxation.

99. A 16-year-old boy was performed an appendectomy. He has been hospitalized for right lower quadrant abdominal pain within 18 hours. The surgical specimen is edematous and erythematous. Infiltration by what of the following cells is the most typical for the process occurring here?

Explanation

Within the first 24hours, the first leukocyte to get into any inflammatory focus are the neutrophils, followed by the monocytes (macrophages) and then lymphocytes.

Neutrophils are the first leukocytes that cross the blood vessel wall to enter inflammatory sites. Under normal conditions, leukocytes are restricted to the center of small blood vessels, where the flow is fastest. In inflammatory sites, where the vessels are dilated, the slower blood flow allows the leukocytes to move out of the center of the blood vessel and interact with the vascular endothelium. Even in the absence of infection, monocytes migrate continuously into the tissues, where they differentiate into macrophages; meanwhile, during an inflammatory response, the induction of adhesion molecules on the endothelial cells, as well as induced changes in the adhesion molecules expressed on leukocytes recruit large numbers of circulating leukocytes, initially Neutrophils and later monocytes, into the site of an infection (inflammatory focus).

First –Neutrophils; second –monocytes and macrophages; third –lymphocytes.

100. ATP synthesis is totally blocked in a cell. How will the value of membrane rest potential change?

Explanation

Resting membrane potential of a cell is maintained by an active transport of sodium and potassium ions through the membrane i.e. the Na+-K+ ATPase pump. This pump which uses ATP, actively transports sodium ions to the extracellular space (outside of the cell) and potassium ions in the opposite direction (inside). Note that more positive charges are pumped to the extracellular space than to the intracellular space (3Na+ to the extracellular space for each 2K+ to the intracellular space), leaving a net deficit of positive ions on the inside; this causes a negative potential inside the cell membrane, which is the resting membrane potential. In the absence of ATP, this pump cannot work and therefore no resting membrane potential is registered.

101. A patient who was previously ill with mastectomy as a result of breast cancer was prescribed radiation therapy. What vitamin preparation has marked radioprotective action caused by antioxidant activity?

Explanation

Tocopherol acetate (Vitamin E) consists of 8 naturally occurring tocopherols of which α-tocopherol is the most active. Vitamin E is an antioxidant which prevents the nonenzymatic oxidation of cell components e.g. polyunsaturated fatty acids by molecular oxygen and free radicals. Consumption of foods rich in these antioxidant compounds has been correlated with a reduced risk for certain types of cancers as well as decreased frequency of certain other chronic health problems. Vitamin E is indicated in radiation disease, rheumatoid arthritis, hypovitaminosis, skin and hepatic diseases etc.

102. A patient with tissue trauma was taken a blood sample for the determination of blood clotting parameters. Specify the right sequence of extrinsic pathway activation:

Explanation

In the intrinsic (internal) coagulation system. Four component complex is formed (Factor VIII, IXa, Phospholipid and Calcium). This complex activates Factor X in the final common pathway. While in the Extrinsic pathway: Factor III (tissue factor); Factor VII and Calcium activates Factor X in the final common pathway.
103. Autopsy of a man who died from chronic cardiovascular collapse revealed \\\"tiger heart\\\". Sidewards of endocardium a yellowish-white banding can be seen; myocardium is dull, dark-yellow. What process caused this pathology?

Explanation

       Intracellular accumulations (parenchymal degeneration or dystrophies). Intracellular fatty degenerations are the abnormal accumulations of triglycerides within parenchymal cells. The liver, heart, kidneys are damaged the most frequently. Fatty degeneration of the heart – Tiger’s heart; fatty degeneration of the liver – Goose liver; fatty degeneration of the kidney – large white kidney.

104. Parents with an ill child consulted an infectionist. They had been working in one of Asian countries for a long time. The child has sallow skin, loss of appetite, laxity, enlarged liver, spleen, peripheral lymph nodes. What protozoal illness can be suspected?

Explanation

The genus Leishmania includes 4 major pathogens: Leishmania donovani; L. tropica; L. Mexicana and L. braziliensis. Leishmania donovani is the cause of kala-azar (visceral leishmaniasis). In visceral leishmaniasis, the organs of the reticuloendothelial system (liver, spleen and bone marrow) are the most severely affected. It occurs in the Middle East, southern Russia, China, India and Sub-saharan Africa. The lifecycle involves the sandfly as the vector and a variety of mammals such as dogs, foxes and rodents as reservoirs.

105. Healthy parents have got a fair-haired, blue-eyed girl. Irritability, anxiety, sleep and feeding disturbance developed in the first months of the infant’s life. Neurological examination revealed developmental lag. What method of genetic investigation should be used for the exact diagnosis?

Explanation

106. The process of heart transplantation determined the viability of myocardial cells. The determination of what myocardium parameter is the most important?

Explanation

Rest potential of cardiomyocytes is the electrical potential difference (voltage) across the cell membrane (between inside and outside of the cell) under resting condition. It is very important because it determines if the myocardium can respond to impulse and contract to pump blood effectively. The condition of the muscle during resting membrane potential is called the polarized state.

107. The calcium canals of cardiomyocytes have been blocked on an isolated rabbit’s heart. What changes in the heart’s activity can result from it?

Explanation

Calcium ion concentration in a myocardial cell is needed both for its action potential propagation (this determines rate of heart beat; plateau stage) and muscle contraction (force). Therefore calcium ion determines both the rate and force of heart contraction. A ↓Ca2+ → ↓Heart Rate and Force.

108. Microscopic examination of the enlarged neck gland of a 14-year-old girl revealed destruction of the tissue structure of the node, absence of the lymph follicles, sclerotic areas and necrosis foci, cell constitution of the node is polymorphous, lymphocytes, eosinophiles, big atypical cells with multilobular nuclei (Beresovsky-Sternberg cells) and mononuclear cells of the large size are present. What is the most likely diagnosis?

Explanation

        Hodgkin’s disease or lymphogranulomatosis is a disorder involving primarily the lymphoid tissue. It is separated from non-hodgkin lymphoma because:

First, it is characterized morphologically by the presence of distinctive neoplastic giant cells called Reed-sternberg’s cells, admixed with a variable inflammatory infiltrate.

Secondly, it is often associated with distinctive clinical features, including systemic manifestations such as fever.

Reed-sternberg cell: classically, it is a large cell, most often binucleate or bilobed, with two halves often appearing as mirror images of each other. Its identification is essential for the histologic diagnosis. The origin of Hodgkin’s lymphoma is unknown.

109. As a result of the damage of one of the Atomic Power Plant reactors the run-out of radioelements took place. People in the high-radiation area were radiated with approximately 250-300 r. They were immediately hospitalized. What changes in the blood count would be typical for the victims?

Explanation

A single accidental exposure to a high dose of radiation during a short period of time is referred to as an acute exposure and may produce biological effects within a short period after exposure. At or above approximately 50rads, acute effects are predictable. 4 periods are distinguished:

·        Initial period (or prodromal phase or primary reaction period): 1 – 2days; begins a few hours after irradiation. Signs include overexcitation of the CNS, increase temperature and lymphopenia.

·        Latent phase: 1 – 2 weeks; only lymphopenia and thrombocytopenia may develop.

·        Manifest phase: hematologic syndrome, CNS and GI syndrome; leukopenia, thrombocytopenia, agranulocytosis (i.e. absence of granulocytes)

·        Recovery phase: gradual restoration of the functions impaired by the sickness.

110. Dystrophic alterations of heart are accompanied with dilation of heart cavities, decreased force of heart contractions, increased blood volume that remains during systole in the heart cavity, vein overfill. What heart condition is it typical for?

Explanation

Increased preload causes dilatation and hypertrophy (eccentric hypertrophy – Myogenic dilation) of the ventricular wall. Sarcomeres duplicate in series causing the individual muscle fibers to increase in length and width. Mitral valve or Aortic valve regurgitation is a common cause. Myogenic dilation is characterized with thinning of the ventricular wall and dilation of the left ventricular and atrial cavities.

111. Nowadays about 50 minor bases have been found in the t-RNA structure besides the main four nitrogenous bases. Choose the minor nitrogenous base:

Explanation

Any nucleotide is composed of a nitrogenous base (purine or pyrimidine), a five-carbon sugar (either ribose or 2-deoxyribose) and phosphate groups.

Major nitrogenous bases:

·        Purine: adenine and guanine

·        Pyrimidine: cytosine, thymine and uracil

Minor nitrogenous bases:

·        Purine: 5-methylcytosine, N6methyladenine, N7methylguanine

·        Pyrimidine (unusual): methylcytosine present in DNA and dihydrouracil present in tRNA.

112. A 60-year-old patient fell ill with obturative jaundice as a result of malignant tumour of the big papillary of the duodenal. Lumen of what anatomical structure is compressed by tumour?

Explanation

The sole longitudinal fold on the mucosa of duodenum which lies on the posteromedial wall of the descending part. It appears as the result of evagination of the bile duct running along the wall. The major duodenal papilla lies at the lower end of the longitudinal fold. On the top of the papilla, there is an opening for bile and pancreatic ducts which delivers pancreatic secretion and bile to duodenal lumen (hepatopancreatic ampulla).

113. Thyrotoxicosis leads to increased production of thyroidal hormones T3 and T4, weight loss, tachycardia, psychic excitement and so on. How do thyroidal hormones effect energy metabolism in the mitochondrion of cells?  

Explanation

A peculiar variant of histotoxic (tissue) hypoxia arises during acute dissociation or uncoupling of processes of oxidation and phosphorylation reactions in respiratory chain. The agents that dissociate process of oxidation and phosphorylation are wide range of substances of exogenous and endogenous origin which includes: hormones of thyroid gland, excess calcium, toxins etc. In a healthy organism, thyroid hormones (thyroxine and triiodothyronine) carry out the function of physiologic regulation of the association of oxidation and phosphorylation degree, together with other functions.

114. While shifting the gaze to the closely situated object the refracting power of eye’s optical mediums will increase by 10 diopters. It results from changing of such eye structure:

Explanation

* Lens: a transparent, crystalline, biconcave structure; suspended from the inner surface of the ciliary body by a ring of radially oriented fibers, the zonule of zinn. Diopter is a unit of measurement of the optical power of a lens or curved mirror.

* Vitreous body: composed of a transparent gel substance that fills the vitreous chamber. It contains hyaluronic acid, widely dispersed collagen fibrils and other proteins and glycoproteins. The fluid component of the vitreous body is called vitreous humor.

* Cornea: anterior window of the eye.

* The cornea is continuous with the sclera. The sclera is composed of dense fibrous connective tissue that provdes attachment for the extrinsic muscles of the eye. It constitutes the “white” of the eye.

* The ciliary body is a ring-like thickening that extends inward just posterior to the level of the corneoscleral junction. Within the ciliary body is the ciliary muscle, a smooth muscle that is responsible for lens accommodation. Contraction of the ciliary muscle changes the shape of the lens, which enables it to bring light rays from different distances to focus on the retina.

115. Necrosis focus appeared in the area of hyperemia and skin edema in few hours after burn. What mechanism strengthens destructive effect in the inflammation area?

Explanation

Acute inflammation has 3 major components: alteration, exudation and proliferation. Alterations in the tissue structure and vascular caliber can lead to injury and increase in blood flow. It is subdivided into primary and secondary.

Secondary alteration is the destruction of cells and tissues by factors which are released and activated in the organism in the primary alteration. These factors are called inflammatory mediators. They can be subdivided into two groups: humoral and cellular mediators.

116. Analeptical remedy of reflective type from the H-cholinomimetics group was given to the patient for restoration of breathing after poisoning with carbon monoxide. What medicine was prescribed to the patient?

Explanation

Lobeline hydrochloride is a N-cholinergic agonists (N-cholinomimetics). It stimulates N-cholinoreceptors located in the CNS, carotid glomerulus, sympathetic and parasympathetic ganglia and adrenal medulla. They are used as respiratory stimulants (analeptics with reflex action) in respiratory arrests.

Atropine sulphate: M-cholinergic antagonist (M-cholinoblocker)

Adrenaline hydrochloride: adrenergic agonist (adrenomimetic)

Mesaton: α-adrenergic agonist (α-adrenomimetic)

Pentamin: ganglioblocker

117. A patient operated on complicated appendicitis has the following changes of blood count: erythrocytes - 4, 0 · 1012/l, Нb - 120 g/l, color index - 0,9, leukocytes - 18 ·109/l,  basophils - 0, eosinophils - 0, myelocytes - 0, juvenile - 0, stab neutrophils - 20, segmentonuclear neutrophils - 53, lymphocytes - 21, monocytes - 5. How is such nuclear shift of leukocytic formula called?

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.

Degenerative shift is characterized by increasing in band's number and appearance of a large number of destructive changed segmented forms (nuclear pyknosis, toxic granularity and cytoplasm vacuolization). This indicates the inhibition of granulocytopoiesis and may occur in the severe course of infectious diseases and in endogenous intoxication.

 Neutrophils: Stab (band): 1-6%                        (20%)↑

                                    Segmented: 47-72%         (53%) normal

                                    Myelocyte: - 0

                                    Metamyelocyte: 0-1%      Juvenile forms (0)

Since there is an elevated content of Stab (band) form of neutrophils, then it is a degenerative left shift.

118. A patient has got a spasm of smooth muscles of bronchi. Activators of what membrane cytoreceptors are phisiologically reasoned to stop an attack?

Explanation

β2 adrenoreceptors are found on the bronchi; when stimulated by adrenomimetics, they dilate the bronchi thereby relieving the spasm of the smooth muscles of bronchi. The cholinergic receptors (M-, N-) constrict the bronchi which will exacerbate the spasm already present in the bronchi.

119. Intrapleural pressure of an individual is being measured. In what phase did he hold his breath if the pressure is - 25 cmH2O?

Explanation

7.5cmHg – Quiet Inspiration

25cmHg – Forced Inspiration
120. Blood sampling for the haematology is recommended to carry out on an empty stomach and in the morning. What changes in blood formula are possible if blood sampling was carried out after food intake?

Explanation

 Leukocytosis is an increase in leukocyte count. Physiological leukocytosis is considered to be a normal response of the organism to certain conditions. Therefore, we can have various forms of physiological leukocytosis, for example:

·        Leukocytosis in newborns

·        Alimentary: usually develops in 2-3hours after meal.

·        Myogenic: may be caused by strenuous physical exertion.

·        Emotiogenic: due to mental stress.

·        Leukocytosis in pregnancy (5-6months of gestation)

The alimentary, myogenic, emotiogenic are usually as a result of redistribution which is transient (with a short-term course) and retain normal proportion of the various forms of leukocytes. The leukocyte commonly involved is the Neutrophil.

121. Glomerular filtration rate (GFR) increased by 20% as a result of prolonged starvation of an individual. The most evident cause of filtration changes under this 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.

122. The ovary specimen colored with hematoxylin-eosin contains a follicle, in which cubic-shaped follicle epithelium cells are placed in 1-2 layers, and scarlet membrane is seen around the ovocyte. Name this follicle:

Explanation

At puberty, a pool of growing follicles is established and continuously maintained from the supply of primordial follicles. A primary oocyte, together with its surrounding flat epithelial cells forms the primordial follicle. Each month 15 – 20 follicles selected from this pool begin to mature, passing through 3 stages namely: primary or preantral; secondary or antral and preovulatory (graafian follicle). As the primary oocyte begins to grow, surrounding follicular cells change from flat to cuboidal and proliferate to produce a stratified epithelium (which can be 1 - 2 layers but usually more) of granulose cells and the unit is called a primary follicle.

123. A  42-year-old man  suffering from gout has increased level of urinary acid in blood. Allopurinol was prescribed to decrease the level of urinary acid. Competitive inhibitor of what enzyme is allopurinol?

Explanation

The end product of the purine nucleotides catabolism in humans and other primates is uric acid (urate) which is excreted in urine. Allopurinol and febuxostat inhibits Xanthine oxidase (XO). Hypoxanthine and Xanthine which is more soluble is excreted in urine. Purine nucleotides (adenine and guanine).  AMP – Adenosine monophosphate; GMP – Guanosine monophosphate

Pyrimidine (thymine, Uracil, cytosine); catabolism of thymine and uracil gives urea, while catabolism of cytosine gives β-alanine.

Allopurinol is a purine analog. It reduces the production of uric acid by competitively inhibiting the last two steps in uric acid biosynthesis that are catalyzed by xanthine oxidase. NOTE: Uric acid is less water soluble than its precursors. When xanthine oxidase is inhibited, the circulating purine derivatives (xanthine & hypoxanthine) are more soluble and therefore are less likely to precipitate. 
124. A child has inhaled a button. Where is it likely to be?

Explanation

Foreign bodies (e.g. button) inspired to the trachea are most likely to be found in the right main bronchus because it is wide and believed to be a continuation of the trachea. It runs almost vertically as a continuation of the trachea. It is much shorter but wider than the left.

125. A patient with serious damage of muscular tissue was admitted to the traumatological department. What biochemical urine index will be increased in this case?

Explanation

Creatine kinase/Creatine phosphokinase is an enzyme present in striated muscles, used to generate energy. When its serum level is elevated it is often an indication of muscle damage caused by injury, muscular dystrophy or cardiac problems. Most forms of muscular dystrophy are associated with decreased creatinine excretion. Creatinine is a break down product of creatine. Normal constituent of urine but can be elevated in muscular dystrophy. 

126. Donor skin transplantation was performed to a patient with extensive burns. On the 8-th day the graft became swollen and changed colour; on the 11-th day graft rejection started. What cells take part in this process?

Explanation

127. As a result of craniocerebral trauma a patient reveals the following symptoms: intention tremor, dysmetry, adiadochokinesis, dysarthria. What structure of the brain is injured?

Explanation

During cerebellar lesions, there  are disturbances in posture, equilibrium and movements. Disturbances in movements: ataxia, asynergia, asthenia (weak muscle contractions with characteristically rapid onset of muscle fatigue), Dysmetria, Intention tremor, astasia (loss of the capacity for sustained tetanic contractions), nystagmus, rebound phenomenon, dysarthria, adiadochokinesis, atonia (lack or impairment of muscle tone).

128. A patient with infectious mononucleosis had been taking glucocorticoids for two weeks. He was brought into remission, but he fell ill with acute attack of chronic tonsillitis. What action of glucocorticoids caused this complication?

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 effects makes the patient susceptible to other infectious diseases (e.g. chronic tonsillitis).

129. Autopsy of a 12-year-old girl revealed: multiple cutaneous hemorrhages (mostly into the skin of buttocks, lower extremities), serous and mucous membrane hemorrhages, cerebral hemorrhages. Adrenal glands show focal necrosis and massive hemorrhages; kidneys show necrotic nephrosis, suppurative arthritis, iridocyclitis, vasculitis. What is the most probable diagnosis?

Explanation

130. A 68-year-old woman can’t move her upper and lower right extremities due to the stroke. Muscle tone of these extremities and their reflexes are increased. There are pathological reflexes. What form of paralysis is it?

Explanation

Movement disorders in paralysis may be in a single limb (monoplegia); both upper or lower extremities (upper paraplegia or lower paraplegia); if half of the body (hemiplegia i.e. one hand and one leg on one side of the body); paralysis of all 4 limbs i.e. lower and upper extremities (tetraplegia).

131. Most participants of Magellan expedition to America died from avitaminosis. This disease declared itself by general weakness, subcutaneous hemorrhages, falling of teeth, gingival hemorrhages. What is the name of this avitaminosis?

Explanation

132. A large-scale reaction with parapertussis and pertussis diagnosticums was made in order to make serological diagnostics of the whooping cough. At the bottom of the test-tubes with diagnosticum of Bordetella parapertussis a granular sediment formed. What anti-bodies did this reaction reveal?

Explanation

Agglutinin – antibody; agglutinogen – antigen

     Agglutination: in this test, the antigen is particulate (e.g. bacteria and red blood cells) or is an inert particle (latex beads) coated with an antigen. Because the antibody (agglutinin) is divalent or multivalent, it cross-links the antigenically multivalent particles and forms a latticework; then clumping (agglutination) can be seen. This reaction can be done in a small cup or tube or with a drop on a slide.

133. Part of the DNA chain turned 180 degree as a result of gamma radiation. What type of mutation took place in the DNA chain?

Explanation

Inversion involve an end-to-end reversal of a segment within a chromosome e.g. ABCDEF becomes ABFEDC  1800.

134. While having the dinner the child choked and aspirated the food. Heavy cough has started, skin and mucose are cyanotic, pulse is rapid, respiration is infrequent, expiration is prolonged. What disorder of the external respiration has the child?

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.

135. A pregnant woman had been having toxicosis with severe repeated vomiting for 24 hours. In the end of the day there appeared tetanic convulsions and fluid loss. What shift of acid-base state caused these changes?

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.

136. After a trauma a 44-year-old patient had a rupture of left palm muscle tendons and of the superficial blood vessels. After operation and removal of the most part of the necrotically changed muscle tissue the bloodstream was normalized. What vessels have helped to restore the bloodstream?

Explanation

The deep palmar arch (arcus Palmaris profundus) is formed by the terminal portion of radial artery and the deep palmar branch of the ulnar artery. The arch resides deep below the tendons of flexors of fingers on the bases of metacarpal bones. The deep palmar arch gives 3 palmar metacarpal arteries; they run along the interosseous muscles to reach the common palmar digital arteries (around the bases of proximal phalanges). Apart from this, they anastomose with the dorsal metacarpal arteries by means of perforating branches. The deep palmar arch can normalize blood flow to the hand in the absence of the superficial palmar arch (superficial blood vessels).

137. An 18-year-old patient has enlarged inguinal lymph nodes, they are painless, thickened on palpation. In the area of genital mucous membrane there is a small-sized ulcer with thickened edges and \\\\\\\"laquer\\\\\\\" bottom of greyish colour. What is the most probable diagnosis?

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).

138. A 45-year-old man applied to the trauma station because of domestic shoulder trauma. Objectively: extension, reduction and pronation functions of the shoulder are absent. What muscle was injured?

Explanation

Teres major muscle is one of the muscles of the shoulder girdle. It originates from the lower angle and lateral border of the scapula; And inserts into the crest of the lesser tubercle of the humerus. It pulls the shoulder to the back (extension); medially rotates and adducts it.

139. Diagnostic scraping was performed to the woman with dysfunctional uterine bleeding. Multiple convoluted glands, ganglially dilated lumens of some glands were revealed histologically in the scrape. Name the type of general pathological process in endometry:

Explanation

Endometrial hyperplasia usually results with conditions of prolonged estrogen excess and can lead to metorrhagia (uterine bleeding at irregular intervals), menorrhagia (excessive bleeding with menstrual periods) or menometrorrhagia. It is classified into 3 types:

·        Simple hyperplasia (cystic glandular hyperplasia)

·        Adenomatous hyperplasia

·        Atypical hyperplasia

Simple hyperplasia is characterized by the presence of large and cystically dilated, varying-sized glands which are lined by atrophic epithelium. Simple endometrial hyperplasias can cause bleeding but are not thought to be premalignant.

140. Tuberculine was introduced intracutaneously to the child for tuberculin test. Marked hyperemia, tissue infiltration developed on the place of injection in 24 hours. What mechanism caused these modifications?

Explanation

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.

Tuberculin (Mantoux) skin test: this test is done by intradermal injection of tuberculoprotein (tuberculin), purified protein derivative (PPD). Type IV hypersensitivity reaction.

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.

141. An intraoperational biopsy of mammal gland has revealed the signs of atypical tissue presented by disorder of parenchyma stroma proportion with domination of the last, gland structures of different size and shape, lined with single-layered proliferative epithelium. What is the most probable diagnosis?

Explanation

Adenoma: benign epithelial tumor from the epithelium of the glands and glandular organs. More often they can be found in the breast, thyroid gland, liver, ovaries, prostate gland, GIT. In the question, it is located in the fibrous stroma – FIBROADENOMA.

142. A 34-year-old patient was diagnosed with chronic glomerulonephritis 3 years ago. Edemata have developed within the last 6 months. What caused the edemata?

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. This proteinuria then degenerates into edema because of the decrease in oncotic pressure in the body.

143. An old woman was hospitalized with acute pain, edema in the right hip joint; the movements in the joint are limited. Which bone or part of it was broken?

Explanation

       The femur consists of a shaft (body) and two ends, superior/proximal and inferior/distal. The neck of the femur is trapezoidal, with its narrow end supporting the head and its broader base being continuous with the shaft. Fractures of the femoral neck is a very common occurrence in older people as a result of a slight stumble if the neck has been weakened by osteoporosis.

144. Concentration of pyruvate is increased in the patient’s blood, the most of which is excreted with urine. What avitaminosis has the 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.

145. A patient with suspected diphtheria went through bacterioscopic examination. Examination of throat swab revealed rod-shaped bacteria with volutin granules. What etiotropic preparation should be chosen in this case?

Explanation

     Etiotropic drug deals directly with the etiological factor (diphtheria toxin). Antidiphtheric antitoxic serum neutralizes the toxin of diphtheria and is employed both as a curative and as a prophylactic agent. Diphtheric anatoxin (diphtheria toxoid) is the diphtheria toxin that has been weakened until it is no longer toxic but is strong enough to induce the formation of antibodies and immunity to the disease.

146. A patient with diabetes mellitus experienced loss of consciousness and convulsions after injection of insulin. What is the result of biochemical blood analysis for concentration of the sugar?

Explanation

One of the most common complications of insulin therapy is hypoglycemia. Normal glucose concentration is 3.3 – 5.5mmol/L. The only option less than 3.3 is 1.5mmol/L which indicates severe hypoglycemia (↓glucose concentration).

147. A patient working at a chemical plant was admitted to the toxicological department with mercury poisoning. What medicine should be used?

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.

 

148. A 63-year-old woman shows symptoms of rheumatoid arthritis. The increase of what blood indices could be the most significant for proving the diagnosis?

Explanation

1.     Rheumatoid (atrophic) arthritis is a chronic progressive inflammatory arthritis of unknown origin involving multiple joints and characterized by disorganization of connective tissue of the synovial membrane and articular cartilage and development of their deformation. Disorganization of the connective tissue cause increase in proteoglycans and glycosaminoglycans (GAGs) concentration in blood. Proteoglycans and GAGs are responsible for the physical properties of ground substance. Main morphological appearance of rheumatoid arthritis is synovitis. It has 3 stages: in the first stage, it is characterized by an acute inflammatory reaction with development of edema, hyperemia and infiltration of lymphocytes, plasma cells and macrophages. Small areas of superficial necrosis or superficial erosions are covered by fibrinoid deposits. Not infrequently 2-3mm “rice bodies” (rice grains) composed of fibrin, fibronectin, collagen and immunoglobulin are present in joint cavities of seropositive patients.

149. An autopsy revealed large (1-2 cm) brownish-red, easy crumbling formations covering ulcerative defects on the external surface of the aortic valve. What is the most likely diagnosis?

Explanation

Polypous ulcerative endocarditis is a morphological form of septic (bacterial) endocarditis. It develops on both sclerotic and intact valves. Large thromboembolic polyp-shaped plaques appear on sclerotic valves. The plaques are easily crumbled and are saturated with calcium which is characteristic for this pathology. After removal of the plaques, ulcerative defects are seen on the sclerotic and deformed cusps of the valves.

150. A   7-year-old   girl has signs of anemia. Laboratory examination revealed pyruvate kinase deficiency in erythrocytes. What process disturbance plays the main role in anemia development?

Explanation

Pyruvate kinase catalyzes the conversion of phosphoenolpyruvate to pyruvate during glycolysis (the third irreversible reaction of glycolysis). The normal, mature erythrocyte lacks mitochondria and is therefore, completely dependent on glycolysis for production of ATP. This high energy compound is required to meet the metabolic needs of the red blood cell and to fuel the pumps necessary for the maintenance of the biconcave, flexible shape of the cell which allows it to squeeze through narrow capillaries. The anemia observed in glycolytic enzyme deficiencies is a consequence of the reduced rate of glycolysis leading to decreased ATP production. The premature death and lysis of red blood cells results in hemolytic anemia. Pyruvate kinase deficiency is restricted to the erythrocytes and produces mild to severe chronic hemolytic anemia.

151. A 5-year-old child who often fells ill with respiratory diseases has eczematous appearances after consumption of some food products, tendency to prolonged course of inflammatory processes. What kind of diathesis can be suspected in this case?

Explanation

Abnormality of constitution, so called diathesis is characterized by pathological reactions on physiological agent. Classification of diathesis:

·        Hemorrhagic: characterized by hemorrhagic reaction to physiological factors.

·        Thymicolymphatic/Lymphohypoplastic: characterized by enlargement of lymphatic nodes, muscular atrophy, individual pale, pastous, predisposing to autoallergic disease, lymphocytosis, angina and other infectious diseases.

·        Neuroarthritic/Gouty: predisposing to arthralgia, arthritis, rheumatism, obesity, gout, psychic disease.

·        Edematic/Exudative: characterized by edema reaction to different environmental factors.

·        Asthenic: expressed in hypodynamia, hypotonia.

152. Low  level  of  albumins  and  fibrinogen was detected in the patient’s blood. Decreased activity of what organelle of the liver hepatocytes can most probably cause it?

Explanation

     Granular or rough endoplasmic reticulum (i.e. rough surface) is a region of endoplasmic reticulum associated with ribosomes. It is the site of protein synthesis and modification of newly synthesized proteins.

Plasma proteins -  albumins  and  fibrinogen
153. A duodenal content smear of a patient with indigestion contains protozoa 10-18 mcm large. They have piriform bodies, 4 pairs of filaments, two symmetrically located nuclei in the broadened part of body. What kind of the lowest organisms is it?

Explanation

Giardia lamblia is pear shape or “clownface” with two nuclei, 4 pairs of flagella. The two nuclei are outlined by adhesive discs. Transmitted by cysts in water. The cysts are oval, have 4 nuclei and have clearly visible axostyles. It causes Giardiasis – bloating, flatulence, foul-smelling, fatty diarrhea. Diagnosis: trophozoites or cysts in stool.

154. A 44-year-old woman complains of common weakness, heart pain, considerable increase of body weight. Objectively: moon-like face, hirsutism, AP-165/100 mm Hg, height - 164 cm, weight - 103 kg; fat is mostly accumulated in the region of neck, upper shoulder girdle, stomach. What is the main pathogenetic mechanism of obesity?

Explanation

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.

155. After a serious viral infection a 3-year-old child has repeated vomiting, loss of consciousness, convulsions. Examination revealed hyperammoniemia. What may have caused changes of biochemical blood indices of this child?

Explanation

        Hyperammonemia can be acquired (e.g. liver disease) or hereditary (e.g. urea cycle enzyme deficiencies). Acquired hyperammonemia may be a result of an acute process e.g. viral hepatitis, ischemia or hepatotoxins. As a result, the detoxification of ammonia (i.e. its conversion to urea) is severely impaired, leading to elevated levels of circulating ammonia.

156. Albinos can’t stand sun impact - they don’t acquire sun-tan but get sunburns. Disturbed metabolism of what amino acid underlies this phenomenon?

Explanation

Tyrosine is formed from phenylalanine by phenylalanine hydroxylase. Albinism refers to a group of conditions in which a defect in tyrosine metabolism results in a deficiency in the production of melanin. These defects result in the partial or full absence of pigment from the skin, hair and eyes. In addition to hypopigmentation, affected individuals have vision defects and photophobia (sunlight hurts their eyes). They are at increased risk for skin cancer.

157. A 25-year-old patient complained of the decreased vision. Accommodation disorders, dilated pupil, lack of reaction for the light were revealed on examination. What muscles function is disturbed?

Explanation

The accommodation mechanism, that is, the mechanism that focuses the lens system of the eye – is essential for a high degree of visual acuity. Accommodation results from contraction or relaxation of the eye ciliary muscle. Contraction causes increased refractive power of the lens and relaxation causes decreased power. When viewing far (remote) objects, the ciliary muscle relaxes and the internal media exert a certain pressure on the layer. The ciliary zonule thus appears to be stretched, which in turn results in flattening of the lens because of radial stretching of its capsule. On the contrary, watching the close objects causes the ciliary muscle to contract and it pulls the ciliary body together with the entire vascular layer anteriorly. Circular fibers of the ciliary muscle narrow the opening (pupil) of the ciliary body where the lens is suspended. These two opposing processes are called accommodation. Paralytic state of this muscle will cause a disorder of accommodation.

158. A patient  with continuous bronchopneumonia was admitted to the therapeutic department. Antibiotic therapy didn’t give much effect. What medication for improvement of immune state should be added to the complex treatment of this patient?

Explanation

Thymalin is an immunostimulator, it’s the complex of polypeptides fractions of thymus gland of horned cattle. It is a drug of first generation. It stimulate cells immune reactions, restore T lymphocytes quantity and function, correlation of T and B lymphocytes, their subpopulations and increase native killers’ activity, intensify phagocytosis and lymphokines production. It is used in complex therapy of immune deficiency diseases and trophic ulcers.

159. Patient with abscess of the cut wound applied to the traumatological department. In order to clean the wound from the pus doctor washed it with 3% hydrogen peroxide. Foam was absent. What caused the absence of the drug activity?

Explanation

Active forms of oxygen (reactive oxygen species) are formed continuously as by-products of aerobic metabolism, through reactions with drugs and environmental toxins, or when the level of antioxidants is diminished, all creating the condition of oxidative stress. One of the protective mechanisms by which the cell minimize the toxic potential of these compounds is by enzymes that catalyze antioxidant reactions. The 3 most important enzymes are glutathione peroxidase, catalase and superoxide dismutase. The superoxide dismutase is specific for converting superoxide to hydrogen peroxide which is then neutralized by catalase or glutathione peroxidase.

Breakdown of H2O2 → H2O + O2 to produce foam. In the absence of these enzymes H2O2 cannot be broken down.

160. Microspecimen of spinal cord contains a nucleus that should be analyzed. Its neurons form motor endings in the skeletal muscles. What nucleus of spinal cord is meant?

Explanation

Anterior gray horn of spinal cord contains the nuclei of lower motor neurons (LMN) which are involved in motor function. These nuclei are present in almost all the levels of spinal cord. Alpha motor neurons in the anterior gray horn are large and multipolar cells. Axons of these neurons leave the spinal cord through the anterior root and end in groups of skeletal muscle fibers called extrafusal fibers. Gamma motor neurons are smaller cells scattered among alpha motor neurons. These neurons send axons to intrafusal fibers of the muscle spindle.

161. Patient  with  injured  muscles  of the lower extremities was admitted to the traumatological department. Due to what cells is repairative regeneration of the muscle fibers and restoration of the muscle function possible?  

Explanation

Satellite cells are interposed between the plasma membrane of the muscle fiber and its external lamina. They are small cells with scant cytoplasm. Satellite cells function as stem cells that, after injury, proliferate to give rise to new myoblasts. As long as the external lamina remains intact, the myoblasts fuse within the external lamina to form myotubes, which then mature into a new fiber.

162. A 50-year-old patient with typhoid fever was treated with Levomycetin, next day his condition became worse, temperature rose to 39, 60 . What caused the complication?

Explanation

Endotoxins: outer cell membrane of most gram negative bacteria. It is not secreted from the cell. It is the structural part of bacteria (lipopolysaccharide) released when the bacteria is lysed. It was originally theorized that endotoxin is released once the bacteria dies. It is now a known fact that bacteria release small amounts of endotoxin as a part of their normal metabolism although the majority is still retained inside the cell. So when the laevomycetin is used, it kills the bacteria but the deterioration of the patient’s condition is as a result of the endotoxin released when the bacteria died. Effects of endotoxin: fever, hypotension, edema, DIC.

163. In the specimen of one of the parts of respiratory system a tubular organ was found. It has low epithelium, well developed muscular tunic, glands and cartilage are absent. Name this organ:

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.

164. A physician examined a patient and found inguinal hernia. Through what anatomic formation does it penetrate into the skin?

Explanation

Anatomically, the saphenous opening (saphenous hiatus) is an oval opening in the upper mid part of the fascia lata of the thigh. It lies 3 – 4cm below and to the side of the pubic tubercle and is about 3cm long and 1.5cm wide. An inguinal hernia is a protrusion of parietal peritoneum and viscera such as the small intestine through a normal or abnormal opening from the cavity in which they belong. The two types of inguinal hernias are direct and indirect inguinal hernias.

165.

A 40-year-old patient complains of intensive heartbeats, sweating, nausea, visual impairment, arm tremor, hypertension. From his anamnesis: 2 years ago he was diagnosed with pheochromocytoma. Hyperproduction of what hormones causes the given pathology?

Explanation

Pheochromocytoma is the most common tumor of the adrenal medulla in adults. Most tumors secrete epinephrine, norepinephrine and dopamine which can cause episodic hypertension. There is increases catecholamines and metanephrines in urine and plasma. Epinephrine stimulates glycogen phosphorylase (rate-limiting enzyme in glycogenolysis i.e. breakdown of glycogen to glucose). This results in hyperglycemia (increase glucose conc. in blood). There is also pronounced sympathetic effects throughout the body like dry mouth.

166. A  58-year-old  patient  with  acute cardiac insufficiency has decreased volume of daily urine - oliguria. What is the mechanism of this phenomenon?

Explanation

Pathogenesis: Acute cardiac insufficiency → ↓cardiac output → ↓blood flow to the kidney → ↓filtration pressure → oliguria.

167.

A 60-year-old man felt asleep after cerebral hemorrhage for a long time. Damage of what structure caused this state?

Explanation

Reticular formation is a diffused mass of neurons and nerve fibers which form an ill-defined meshwork of reticulum in central portion of the brainstem. Functions: Ascending reticular activating system (ARAS) and descending reticular system. The ARAS is concerned with arousal, alertness, attention and wakefulness, emotional reactions, learning processes and conditioned reflexes. Hence, tumor or lesion in ARAS leads to prolonged sleeping or coma.

168.

Tuberculosis can be treated by means of combined chemotherapy that includes substances with different mechanisms of action. What antituberculous medication inhibits transcription of RNA into DNA in mycobacteria?

Explanation

169.

A  patient  experienced  a  sudden temperature rise up to 390C. After 6 hours the temperature normalized. On the 2-nd day the attack recurred: in the period of paroxysm the temperature reached 410C, apyrexial period began after 8 hours. What type of temperature profile is it?

Explanation

* Febris intermittens: characterized by regular alternation of brief attacks of fever (paroxysms) with feverless periods (apyrexia). Attacks occur every 3rd day, 2nd day or everyday. Increase temperature persists for several hours, drops to normal and then rises again.

* Febris continua/persistent: elevated temperature persists at a high level, difference between morning and evening temperature does not exceed 10C.

* Febris recurrens: characterized by longer periods of pyrexia than intermittent (5-6days). Question says every 4 days.

* Febris hectic: 3-50C (difference in temperature).

* Febris remittens: difference in temperature exceeds 10C but temperature never falls to normal.

170.

Cerebral trauma caused increase of ammonia formation. What amino acid takes part in removal of ammonia from cerebral tissue?

Explanation

Substances absorbed into the bloodstream from the intestine pass through the liver, where toxins are normally removed. Many of these toxins (such as ammonia) are normal breakdown products of the digestion of protein.  Ammonia is produced by amino acid metabolism and intestinal urease-positive bacteria. In physiological conditions, it is mostly present as ammonium (NH4+) in serum. The urea or ornithine cycle, which is fully expressed in the liver exclusively, serves to converts NH4+ to urea prior to renal excretion and to maintain low serum concentrations. 

NH3 + α-ketoglutarate → Glutamate

α-ketoglutarate is used up which leads to:

·        ↑glutamate → ↑GABA (inhibitory neurotransmitter)

·        Inhibition of citric acid cycle/tricarboxylic acid cycle; this causes impairment of ATP formation.

·        Inhibition of metabolism of amino acids (impairment of transamination reactions).

 

NH3 + Glutamate → Glutamine

Glutamine is an amide of glutamic acid which provides a non-toxic storage and transport form of ammonia (NH3). Ammonia increase synthesis of glutamine in brain. Accumulation of glutamine in brain results in elevation of osmotic pressure in nervous cells leading to brain edema.

                                   

                                    NH3 + H+ → NH4+

In blood ammonia (NH3) is represented as ammonium ion (NH4+). Accumulation of ammonium ion impairs transport of ions (Na+, K+) through cell membranes and failure of transmission of nerve impulse. 

 

171. Microscopic examination of the sputum of a patient with pneumonia occasionally revealed some larvae. Eosinophiles were detected on blood examination. What helminthiasis can be diagnosed?

Explanation

Ascaris lumbricoides (giant roundworm) is the causative agent of Ascariasis. Transmission: fecal-oral; eggs are visible in faeces under microscope. Some patients may have pulmonary symptoms or neurological disorders during migration of the larvae. A bolus of worms may obstruct the intestine; migrating larvae may cause pneumonitis 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.

172.

A 40-year-old woman was admitted to the infectious diseases department with high body temperature. Objectively: marked meningeal symptoms. A spinal cord punction was made. What anatomic formation was puncturated?

Explanation

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.

173.

The energy inputs of a healthy man have been measured. In what state was the patient if his energy inputs were less than the main exchange?

Explanation

       Sleep is the natural periodic state of rest for mind and body with closed eyes characterized by partial or complete loss of consciousness. Sleep is unconsciousness from which the person can be aroused by sensory or other stimuli. It is to be distinguished from coma, which is unconsciousness from which the person cannot be aroused. During sleep, most of the body functions are reduced to basal level or even below the basal level. Therefore, power inputs can be lower than basal level during sleep. Unlike rest where it remains at the basal level or higher.

174.

Examination of a newborn boy’s genitals revealed a cleft of urethra that opens on the inferior surface of his penis. What developmental anomaly is meant?

Explanation

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.

175.

To prevent long-term effects of 4-day malaria a 42-year-old patient was prescribed primaquine. On the 3-rd day from the begin of treatment there appeared stomach and heart pains, dyspepsia, general cyanosis, hemoglobinuria. What caused side effects of the preparation?

Explanation

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is an inherited disease characterized by hemolytic anemia caused by the inability to detoxify oxidizing agents. Diminished G6PD activity impairs the ability of the cell to form the NADPH that is essential for the maintenance of the reduced glutathione pool. This results in a decrease in the cellular detoxification of free radicals and peroxides formed within the cell. Although G6PD deficiency occurs in all cells of the affected individual, it is most severe in erythrocytes where the pentose phosphate pathway provides the only means of generationg NADPH. Some patients with G6PD deficiency develop hemolytic anemia if they are treated with an oxidant drug (e.g. antimalarial – primaquine, chloroquine); ingest fava beans or contract a severe infection.

176.

A 17-year-old boy fell seriously ill, body temperature rose up to 38,50C,  there is cough, rhinitis, lacrimation, nasal discharges. What kind of inflammation is it?

Explanation

Catarrhal inflammation is one of the morphologic patterns in acute inflammation. In this type, a surface inflammation is associated with greatly increased secretion of clear mucus (nasal discharges). Rhinitis is inflammation of mucous lining of the nose.

177.

A genetics specialist analyzed the genealogy of a family and found that both males and females may have the illness, not across all the generations, and that healthy parents may have ill children. What is the type of illness inheritance?

Explanation

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.

178.

A patient who has been treated with diazepam on account of neurosis complains of toothache. Doctor administered him an analgetic, but its dose was lower than average therapeutic dose. What phenomenon did the doctor take into account while prescribing the patient an underdose?

Explanation

179.

Inflammatory process of modified subserous layer around cervix of the uterus caused an intensive pain syndrome. In what region of genitals does the pathological process take place?

Explanation

The space between the peritoneal plates of the broad ligament mostly in its inferior portion is filled with fat called the parametrium. Inflammation of the fat – parametritis, is common in clinical practice.

180. Analysis of amniotic fluid that was obtained as a result of amniocentesis (puncture of amniotic sac) revealed cells the nuclei of which contain sex chromatin (Barr’s body). What can it be evidence of?

Explanation

Barr body is an inactive X-chromosome. A normal female has one barr body XX; so in turner’s syndrome, there is no barr body because the only X present is the active one (45 XO); likewise in a normal male fetus XY

181.

A 2-year-old child has got intestinal dysbacteriosis, which resulted in hemorrhagic syndrome. What is the most likely cause of hemorrhage of the child?

Explanation

A true vitamin K deficiency is unusual because adequate amounts are generally produced by intestinal bacteria or obtained from the diet. If the bacterial population in the gut is decreased e.g. by antibiotics (leading to dysbacteriosis), the amount of endogenously formed vitamin is depressed and this can lead to hypoprothrombinemia (↓prothrombin) which results in hemorrhagic syndrome.

182.

Autopsy of a 46-year-old man revealed multiple brown-and-green layers and hemorrhages on the mucous membrane of rectum and sigmoid colon; slime and some blood in colon lumen; histologically - fibrinous colitis. In course of bacteriological analysis of colon contents S.Sonne were found. What is the most probable diagnosis?

Explanation

Dysentery refers to bloody diarrhea with mucus. It refers to diarrhea with abdominal cramping and tenesmus in which loose stools contain blood, pus and mucus. Bacillary dysentery is caused by shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei. Morphology: it has 4 stages namely: catarrhal colitis; fibrinous colitis; ulcer formation (ulcerative colitis); healing of the wound. Complications of dysentery includes perforation, intraintestinal hemorrhage and eventually death may result from intestinal or extraintestinal complications.

183.

A patient had been ill with bronchial asthma for many years and died from asthmatic fit. Histologic lung examination revealed: lumen of bronchioles and small bronchis contain a lot of mucus with some eosinophils, there is sclerosis of alveolar septums, dilatation of alveoli lumen. What mechanism of development of hypersensibility reaction took place?

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)

184.

To anaesthetize the surgical treatment of burn surface, a patient was intravenously injected a medication for short-acting narcosis. 1 minute later the patient being under anaesthesia showed increased blood pressure, tachycardia, increased tone of skeletal muscles; reflexes remained. After recovering from anaesthesia the patient had disorientation and visual hallucinations. What medication was the patient injected?

Explanation

Ketamin is an intravenous anesthesia. It is an antagonist of glutamic acid, blocking the actions of this excitatory transmitter. The drug is a cardiovascular stimulant and this action may lead to an increase in intracranial pressure. Reactions such as disorientation, excitation and hallucinations can occur during recovery from ketamin anesthesia. It has no effect on laryngeal reflexes. Skeletal muscle tone, heart rate, arterial blood pressure and cerebrospinal fluid pressure can be increased by ketamin.

185.

Desulfiram is widely used in medical practice to prevent alcoholism. It inhibits aldehyde dehydrogenase. Increased level of what metabolite causes aversion to alcohol?

Explanation

Disulfiram inhibits acetaldehyde dehydrogenase (acetaldehyde accumulates, contributing to hangover symptoms).

Fomepizole inhibits alcohol dehydrogenase and is an antidote for methanol or ethylene glycol poisoning.

186. A 1-year-old child with symptoms of muscle involvement was admitted to the hospital. Examination revealed carnitine deficiency in his muscles. What process disturbance is the biochemical basis of this pathology?

Explanation

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.

187.

A patient died from acute cardiac insufficiency. The histological examination of his heart revealed the necrotized section in myocardium of the left ventricle, which was separated from undamaged tissue by the zone of hyperemic vessels, small hemorrhages and leukocytic infiltration. What is the most likely diagnosis?

Explanation

188.

Kidneys of a man under examination show increased resorbtion of calcium ions and decreased resorbtion of phosphate ions. What hormone causes this phenomenon?

Explanation

Parathyroid hormone: secreted by chief cells of parathyroid gland. Effects include:

↑bone resorption of Ca2+ and PO43- → ↑their plasma levels

↑kidney reabsorption of Ca2+ in distal convoluted tubule → ↑ Ca2+ plasma level

↓reabsorption of PO43- in proximal convoluted tubule → ↓ PO43- plasma levels

↑Calcitriol (vit D3) production by stimulating kidney 1α-hydroxylase in proximal convoluted tubule. It increases Ca2+ and PO43- absorption in the intestine.

In general, parathyroid hormone ↑ Ca2+ plasma level but ↓ PO43- plasma levels. Abnormal synthesis (↑synthesis) of parathyroid hormone can lead to hypercalcemia and hypophosphatemia.

Calcitonin is secreted by parafollicular cells (C cells of the thyroid gland). It ↓bone resorption of Ca2+. It opposes actions of parathyroid hormone. But its not important in normal Ca2+ homeostasis. Calcitriol ↑ circulating Ca2+ ions as a means of enhancing intestinal absorption of calcium (NB: Calcitriol production is dependent on parathyroid hormone).
189. An isolated cell of human heart automatically generates excitation impulses with frequency 60 times pro minute. What structure does this cell belong to?

Explanation

The sinoatrial (SA) node is a small strip of modified cardiac muscle, situated in the superior part of lateral wall of right atrium, just below the opening of superior vena cava. The fibers of this node do not have contractile elements. SA node is called the pacemaker because the rate of production of impulse (rhythmicity) is higher in SA node than in other parts. The rate is 60-100/min and higher during tachycardia when stimulated by sympathetic effects. Atrioventricular (AV) node is 40-60/min.

190. While preparing a patient to the operation the heart chambers’ pressure was measured. In one of them the pressure changed during one heart cycle from 0 to 120 mm Hg. What chamber of heart was it?

Explanation

          Pressure in each heart chambers:

 

    Diastole (mmHg)

      Systole (mmHg)

Left ventricle

               4-12

            90-140

Right ventricle

               0-8

             15-28

Left atrium

          -2 to +6

               6-20

Right atrium

          -2 to +6

               2-14

Only the left ventricle can range from 0-120mmHg

191.

Part of alveoles of a preterm infant didn’t spread because of enhanced elastic recoil of lungs. How can this recoil be reduced?

Explanation

Surfactant is particularly important for survival of the premature infant. When surfactant is insufficient, the air-water (blood) surface membrane tension becomes high, bringing great risk that alveoli will collapse during expiration. As a result, respiratory distress syndrome (RDS) develops. This is a common cause of death in the premature infant. Recent development of artificial surfactant and treatment of premature babies with glucocorticoids to stimulate surfactant production have reduced the mortality associated with RDS and allowed survival of some babies as young as 5.5months of gestation.

192.

A young man has a painless formation without marked borders in the soft tissues of his thigh. On the tissue bioptate the formation looks like flesh of fish and consists of immature fibroblast-like cells with multiple mitosis growing through the muscles. What is the most likely diagnosis?

Explanation

Macroscopically, sarcoma looks like “fish flesh”. Fibrosarcoma occurs in deep soft tissue sites, showing increased fibroblastic cells, anaplasia and abundant mitotic figures. It looks like node or encapsulated formation.

193.

In course of prophylactic medical examination a 7-year-old boy was diagnosed to have daltonism. Parents are healthy, color vision is normal. But grandfather from the mother’s side has the same disorder. What is the type of inheriting of this anomaly?

Explanation

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.

194. Objective examination of a patient revealed: slender figure, big skull, highly developed frontal region of face, short extremities. What constitutional type is it characteristic for?

Explanation

195.

A 38-year-old patient died during intractable attack of bronchial asthma. Histologic examination revealed mucus accumulation in bronchial lumen, a lot of fat cells (labrocytes) in the wall of bronchis, many of them are in the state of degranulation, there are also a lot of eosinophils. What pathogenesis of bronchial changes is it?

Explanation

* Type I: Allergic and atopic disorders (e.g. rhinitis, hay fever, asthma); Anaphylaxis. Presentation – immediate, anaphylactic, atopic

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)

196.

A patient with thrombophlebitis of lower extremities had got chest pains, blood spitting, growing respiratory failure that caused his death. Autopsy revealed multiple pulmonary infarctions. What is the most probable reason of their development?

Explanation

Pulmonary embolism is the most common and fatal form of venous thromboembolism in which there is occlusion of pulmonary arterial tree by thromboemboli. Pulmonary emboli are more common in hospitalized or bedridden patients. The majority of emboli arise from the deep veins of the lower extremities; most of the fatal ones arise from the ileofemoral veins. Consequences of thromboembolism include pulmonary infarction in which pyramidal segments (or ‘triangular’ segments) of hemorrhagic infarction are seen at the periphery of the lung. Detachment of thrombi from the thrombophlebitis site in the lower limbs produces a thromboembolus that flows through venous drainage into the large veins draining into the right side of the heart and then to the pulmonary circulation where they embolize.

197. Diabetes mellitus causes ketosis as a result of activated oxidation of fatty acids. What disorders of acid-base equilibrium may be caused by excessive accumulation of ketone bodies in blood?

Explanation

When the rate of formation of ketone bodies is greater than the rate of their use, their levels begin to rise in blood (ketonemia) and eventually in the urine (ketonuria). These two conditions are seen most often in cases of uncontrolled type I diabetes mellitus. In such individuals, high fatty acid degradation produces excessive amounts of acetyl CoA. It also depletes the NAD+ pool and increases the NADH pool, which slows the citric acid cycle. This forces the excess acetyl CoA into the ketone body pathway. An elevation of the ketone body concentration in  the blood results in metabolic acidosis.
198.

A woman with 0 (I) blood group has born a child with AB blood group. This woman’s husband has A blood group. What genetic interaction explains this phenomenon?

Explanation

199.

A 30-year-old woman was diagnosed with insufficiency of exocrinous function of pancreas. Hydrolisis of what nutrients will be disturbed?

Explanation

200. A 39-year-old woman has madescence in the region of mammilla, a small ulcer with inflammatory hyperemia and cutaneous edema. Histologic examination of tissue sampling from this area revealed in the malpighian layer of thickened epidermis atypical cells with light and optically empty cytoplasm, with no intracellular bridges. Such cells were also found in the orifice of big mammal gland ducts. What is the most probable diagnosis?

Explanation

Paget’s disease of nipple: the nipple bears a crusted, scaly eczematoid lesion with a palpable subareolar mass in about half the cases. Microscopically, the skin lesion is characterized by the presence of Paget’s cells singly or in small clusters in the epidermis. These cells are larger than the epidermal cells, spherical having hyperchromatic nuclei with cytoplasmic halo that stains positively with mucicarmine. Paget’s cells show an empty cytoplasm.