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Question 1
Incorrect
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With regards to splenic micro-architecture which is not contained within the red pulp
Your Answer: Sinusoids
Correct Answer: Malpighian corpuscles
Explanation:Red pulp is responsible for mechanical filtration of red blood cells and is composed of sinusoids, which are filled with blood, splenic cords of reticular fibers and a marginal zone bordering on white pulp. White pulp provides an active immune response through humoral and cell-mediated pathways. Composed of nodules, called Malpighian corpuscles. These are composed of: lymphoid follicles, rich in B-lymphocytes and periarteriolar lymphoid sheaths (PALS), rich in T-lymphocytes.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 2
Correct
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Which of the following is matched correctly with regard to stem cells of the bone marrow?
Your Answer: Hemopoietic stem cells - basophils
Explanation:Hematopoietic stem cells (HSCs) or hemocytoblasts are the stem cells that give rise to all the other blood cells through the process of haematopoiesis. They give rise to both the myeloid and lymphoid lineages of blood cells. (Myeloid cells include monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells, and megakaryocytes or platelets. Lymphoid cells include T cells, B cells, and natural killer cells.)
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This question is part of the following fields:
- Haematology
- Medicine
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Question 3
Correct
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Question 4
Correct
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Why is tissue plasminogen activator (tPa) a valuable treatment used in myocardial infarction and stroke?
Your Answer: It forms plasmin from its inactive precursor
Explanation:tPA is a serine protease involved in the breakdown of blood clots. It functions by converting plasminogen, an inactive precursor, into plasmin, an active enzyme. Plasmin then degrades fibrin, the main protein component of blood clots, leading to clot dissolution. This mechanism is particularly valuable in the treatment of myocardial infarction (heart attack) and ischemic stroke, where timely dissolution of the clot can restore blood flow to affected tissues and reduce damage.
Therefore, the correct answer is:
- It forms plasmin from its inactive precursor
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This question is part of the following fields:
- Haematology
- Medicine
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Question 5
Correct
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Question 6
Correct
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Question 7
Correct
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90% of erythropoietin necessary for haemopoesis is produced by the kidneys, the remainder is formed in the?
Your Answer: Liver
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 8
Correct
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The intrinsic pathway of coagulation is activated by which of the following?
Your Answer: Collagen fibers underlying the endothelium
Explanation:The contact activation (intrinsic) pathway begins with formation of the primary complex on collagen by high-molecular-weight kininogen (HMWK), prekallikrein, and FXII (Hageman factor).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 9
Correct
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Which of the following is a precursor to the tissue macrophage?
Your Answer: Monocyte
Explanation:Monocytes are a type of white blood cell, or leukocyte. They are the largest type of leukocyte and can differentiate into macrophages or dendritic cells.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 10
Incorrect
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Bone marrow barrier is important to:
Your Answer: All of the above
Correct Answer: Allow mature red blood cells to pass into circulation
Explanation:The blood vessels of the bone marrow constitute a barrier, inhibiting immature blood cells from leaving the marrow. Only mature blood cells contain the membrane proteins, such as aquaporin and glycophorin, that are required to attach to and pass the blood vessel endothelium.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 11
Correct
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Vitamin B12 is transported from the enterocytes to the bone marrow by which factor?
Your Answer: Transcobalamin II (TC IIi)
Explanation:B12 must be attached to IF for it to be efficiently absorbed, as receptors on the enterocytes in the terminal ileum of the small bowel only recognize the B12-IF complex. Once the IF/B12 complex is recognized by specialized ileal receptors, it is transported into the portal circulation. The vitamin is then transferred to transcobalamin II (TC-II/B12), which serves as the plasma transporter.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 12
Correct
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Which of the following is true regarding platelets?
Your Answer: Normally have a half-life of about 8 days
Explanation:Platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation. They have a half life of 5-9 days.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 13
Correct
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Platelets are stored in this body organ.
Your Answer: Spleen
Explanation:Megakaryocyte and platelet production is regulated by thrombopoietin. Each megakaryocyte produces between 1,000 and 3,000 platelets during its lifetime. An average of 1011 platelets are produced daily in a healthy adult. Reserve platelets are stored in the spleen, and are released when needed by splenic contraction induced by the sympathetic nervous system.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 14
Correct
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Question 15
Incorrect
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Which of the following vitamin deficiencies is associated with xerophthalmia?
Your Answer: Vitamin D
Correct Answer: Vitamin A
Explanation:Xerophthalmia caused by a severe vitamin A deficiency is described by pathologic dryness of the conjunctiva and cornea. The conjunctiva becomes dry, thick and wrinkled. If untreated, it can lead to corneal ulceration and ultimately to blindness as a result of corneal damage.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 16
Correct
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Lymphoid stem cells give rise to the following cells:
Your Answer: T cells, b cells and natural killer cells
Explanation:T Cells, B Cells and NK Cells (and all other Innate lymphoid cells) are unique to the lymphocyte family, but dendritic cells are not. Dendritic cells of identical appearance but different markers are spread throughout the body, and come from either lymphoid and myeloid lineages.
Myeloid stem cells lead to myeloblasts, which evolve into macrophages, monocytes, neutrophils, basophils, and eosinophils.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 17
Correct
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The structure of haemoglobin A in adults includes
Your Answer: Haem, globin polypeptide chains α and β
Explanation:Haemoglobin A (HbA), also known as adult haemoglobin or α2β2, is the most common human haemoglobin tetramer, comprising over 97% of the total red blood cell haemoglobin. It consists of two alpha chains and two beta chains.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 18
Correct
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Which enzyme deficiency causes Beriberi?
Your Answer: Thiamine
Explanation:Beriberi refers to a cluster of symptoms caused primarily by thiamine (vitamin B1) deficiency. Symptoms of beriberi include weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the limbs, and periods of irregular heart rate.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 19
Correct
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All of the following are Vitamin K-dependent clotting factors except:
Your Answer: Factor XI
Explanation:Activated Vitamin K is used to gamma carboxylate (and thus activate) certain enzymes involved in coagulation: Factors II, VII, IX, X, and protein C and protein S. Inability to activate the clotting cascade via these factors leads to the bleeding symptoms
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This question is part of the following fields:
- Haematology
- Medicine
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Question 20
Correct
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Where is retinol mainly stored?
Your Answer: Liver
Explanation:Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids (most notably beta-carotene). The liver stores a multitude of substances, including glucose (in the form of glycogen), vitamin A (1–2 years’ supply), vitamin D (1–4 months’ supply), vitamin B12 (3–5 years’ supply), vitamin K, iron, and copper.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 21
Incorrect
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Which vitamin is found in NAD and NADP?
Your Answer: Vitamin B6
Correct Answer: Vitamin B3
Explanation:In organisms, NAD can be synthesized from simple building-blocks (de novo) from the amino acids tryptophan or aspartic acid. In an alternative fashion, more complex components of the coenzymes are taken up from food as the vitamin called niacin (vitamin B3)
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This question is part of the following fields:
- Haematology
- Medicine
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Question 22
Correct
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What is the function of Activated protein C?
Your Answer: Inactivates factor Va
Explanation:Activated Protein C (APC) is a crucial protein in the regulation of blood coagulation. Its primary functions include:
- Inactivating Factor Va: APC inactivates Factor Va, which is a cofactor for the conversion of prothrombin to thrombin by Factor Xa. By inactivating Factor Va, APC reduces thrombin formation, thereby acting as an anticoagulant.
- Inactivating Factor VIIIa: APC also inactivates Factor VIIIa, another cofactor that assists Factor IXa in the conversion of Factor X to Factor Xa. This further contributes to its anticoagulant effect.
These actions help to regulate blood clotting and prevent excessive thrombosis.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 23
Correct
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Where is the most erythropoietin produced?
Your Answer: Kidneys
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 24
Correct
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Vitamin K deficiency can be found in which of the following condition?
Your Answer: Cholestatic jaundice
Explanation:Vitamin K1-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of a vitamin K1-antagonist such as warfarin, or, very rarely, by nutritional vitamin K1 deficiency.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 25
Correct
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Inactive cellular marrow is called
Your Answer: Yellow marrow
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 26
Correct
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The extrinsic coagulation pathway is initiated by activation of which clotting factor?
Your Answer: Factor VII
Explanation:The tissue factor pathway (extrinsic) begins following damage to the blood vessel. FVII leaves the circulation and comes into contact with tissue factor (TF) expressed on tissue-factor-bearing cells (stromal fibroblasts and leukocytes), forming an activated complex (TF-FVIIa).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 27
Correct
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What is the average life span of neutrophils?
Your Answer: 24 hours
Explanation:The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 90 hours.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
Correct
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Which of the following conditions is associated with eosinophilia?
Your Answer: Ascaris
Explanation:Eosinophilia can be idiopathic (primary) or, more commonly, secondary to another disease. In the Western World, allergic or atopic diseases are the most common causes, especially those of the respiratory or integumentary systems. In the developing world, parasites are the most common cause e.g. Ascaris
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This question is part of the following fields:
- Haematology
- Medicine
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Question 29
Correct
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Which one of the following is necessary to activate plasminogen to plasmin?
Your Answer: tPA
Explanation:In circulation, plasminogen adopts a closed, activation resistant conformation. Upon binding to clots, or to the cell surface, plasminogen adopts an open form that can be converted into active plasmin by a variety of enzymes, including tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), kallikrein, and factor XII (Hageman factor).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 30
Correct
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Choose the correct statement regarding the protein C/S system?
Your Answer: The protein C/S complex inactivates factor Va and VIIIa
Explanation:The best characterized function of Protein S is its role in the anti coagulation pathway, where it functions as a cofactor to Protein C in the inactivation of Factors Va and VIIIa.
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This question is part of the following fields:
- Haematology
- Medicine
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