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Question 1
Incorrect
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Which statement is correct about the clinical state of methemoglobinemia?
Your Answer: Methaemoglobin, present in the circulation in small quantities, can resemble cyanosis.
Correct Answer: May arise due to a hereditary deficiency of NADH.
Explanation:Methaemoglobin is a form of haemoglobin that contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. Spontaneously formed methaemoglobin is normally reduced by protective enzyme systems, e.g., NADH methaemoglobin reductase, hence a deficiency of NADH may result in increased levels of methaemoglobin
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This question is part of the following fields:
- Haematology
- Physiology
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Question 2
Incorrect
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Which of the following foods contain Vitamin B 12?
Your Answer: Tomatoes
Correct Answer: Liver, meat
Explanation:No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved food sources of B12 are animal products (meat, fish, dairy products).
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This question is part of the following fields:
- Haematology
- Physiology
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Question 3
Incorrect
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Which of the following foods do NOT contain high levels of folate?
Your Answer: Yeast
Correct Answer: Green leafy vegetables
Explanation:Folate naturally occurs in a wide variety of foods, including vegetables (particularly dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, poultry and meat, eggs, seafood, grains, and some beers. Avocado, beetroot, spinach, liver, yeast, asparagus, and Brussels sprouts are among the foods with the highest levels of folate
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This question is part of the following fields:
- Haematology
- Physiology
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Question 4
Incorrect
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What is the function of Activated protein C?
Your Answer: Activates factor V
Correct Answer: Inactivates factor Va
Explanation:Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogen, the activated form of which plays an important role in regulating anticoagulation, inflammation, cell death, and maintaining the permeability of blood vessel walls in humans and other animals. Activated protein C (APC) performs these operations primarily by proteolytically inactivating proteins Factor Va and Factor VIIIa.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 5
Incorrect
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Which of the following is true regarding platelets?
Your Answer:
Correct 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
- Physiology
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Question 6
Incorrect
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Question 7
Incorrect
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Question 8
Incorrect
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With regard to the spleen which of the following has the correct match?
Your Answer:
Correct Answer: Periarteriolar lymphoid sheets - T lymphocytes
Explanation:The spleen consists of:Red pulp – responsible for mechanical filtration of red blood cells. Red pulp contains sinusoids, which are filled with blood, splenic cords of reticular fibers and a marginal zoneWhite pulp – responsible for 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, rich in T-lymphocytes
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This question is part of the following fields:
- Haematology
- Physiology
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Question 9
Incorrect
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Where is retinol mainly stored?
Your Answer:
Correct 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
- Physiology
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Question 10
Incorrect
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Bone marrow barrier is important to:
Your Answer:
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
- Physiology
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Question 11
Incorrect
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Why is tissue plasminogen activator (tPa) a valuable treatment, used clinically in myocardial infarction and stroke?
Your Answer:
Correct Answer: It forms plasmin from its inactive precursor
Explanation:tPA is used in some cases of diseases that feature blood clots, such as pulmonary embolism, myocardial infarction, and stroke, in a medical treatment called thrombolysis. The most common use is for ischemic stroke. As an enzyme, it catalyses the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 12
Incorrect
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Which one of the following is necessary to activate plasminogen to plasmin?
Your Answer:
Correct 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
- Physiology
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Question 13
Incorrect
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One of the cells of the bone marrow that are responsible for forming the various forms of differentiated blood cells are called?
Your Answer:
Correct Answer: Hematopoietic stem cell
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 are derived from mesoderm and located in the red bone marrow, which is contained in the core of most bones.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 14
Incorrect
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Select one true statement about haemoglobin synthesis…
Your Answer:
Correct Answer: Occurs in the cytosol of developing red cells.
Explanation:Haemoglobin (Hb) is synthesized in a complex series of steps. The haem part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in the cytosol. Production of Hb continues in the cell throughout its early development from the proerythroblast to the reticulocyte in the bone marrow.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 15
Incorrect
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Vitamin B12 is transported from the enterocytes to the bone marrow by which factor?
Your Answer:
Correct 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
- Physiology
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Question 16
Incorrect
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Choose the most correct answer, what reduces affinity for oxygen in haemoglobin?
Your Answer:
Correct Answer: All the options are true
Explanation:The strength with which oxygen binds to haemoglobin is affected by several factors. These factors shift or reshape the oxyhaemoglobin dissociation curve. A rightward shift indicates that the haemoglobin under study has a decreased affinity for oxygen. The causes of shift to right can be remembered using the mnemonic, CADET, face Right! for CO2 and CO, Acid (H+), 2,3-DPG, Exercise and Temperature.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 17
Incorrect
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In the normal adult, haematopoiesis is present
Your Answer:
Correct Answer: Axial skeleton and proximal ends of long bones
Explanation:In children, haematopoiesis occurs in the marrow of the long bones such as the femur and tibia. In adults, it occurs mainly in the pelvis, cranium, vertebrae, and sternum.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 18
Incorrect
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The following play a role in regulation of intestinal iron absorption except:
Your Answer:
Correct Answer: Urinary iron excretion rate
Explanation:The human body’s rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, dietary intake, the extent to which the bone marrow is producing new red blood cells, the concentration of haemoglobin in the blood, and the oxygen content of the blood. Classic examples of genetic iron overload includes hereditary hemochromatosis (HH) and the more severe disease juvenile hemochromatosis (JH).
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This question is part of the following fields:
- Haematology
- Physiology
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Question 19
Incorrect
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Which of the following conditions is procoagulant?
Your Answer:
Correct Answer: Factor V Leiden
Explanation:Factor V Leiden is a variant (mutated form) of human factor V (one of several substances that helps blood clot) that causes an increase in blood clotting (hypercoagulability). With this mutation, the anticoagulant protein secreted (that stops factor V from causing inappropriate clotting) is inhibited, leading to an increased tendency to form dangerous, abnormal blood clots. Christmas disease is otherwise known as Haemophilia B. Hypothrombinaemia and afibrinogenemia both result in inadequate blood clotting.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 20
Incorrect
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The extrinsic coagulation pathway is initiated by activation of which clotting factor?
Your Answer:
Correct 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
- Physiology
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Question 21
Incorrect
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What is the main function of vitamin E?
Your Answer:
Correct Answer: It is an antioxidant
Explanation:Vitamin E has many biological functions, the antioxidant function being the best known. Other functions include enzymatic activities, gene expression, and neurological function(s).
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This question is part of the following fields:
- Haematology
- Physiology
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Question 22
Incorrect
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Question 23
Incorrect
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Regarding Iron stores, which of the following contains the highest proportion of total body iron?
Your Answer:
Correct Answer: Haemoglobin
Explanation:Most well-nourished people in industrialized countries have 4 to 5 grams of iron in their bodies. Of this, about 2.5 g is contained in the haemoglobin needed to carry oxygen through the blood, and most of the rest (approximately 2 grams in adult men, and somewhat less in women of childbearing age) is contained in ferritin complexes that are present in all cells, but most common in bone marrow, liver, and spleen.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 24
Incorrect
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What is the reason for a deranged thrombin clotting time?
Your Answer:
Correct Answer: Heparin therapy
Explanation:Thrombic clotting time is also known as thrombin time. It is clinically performed to determine the therapeutic levels of heparin. After plasma is isolated from the blood, bovine thrombin is added to it and the time it takes from the addition to clot is recorded. The reference interval is usually <21s. deranged results are indicative of heparin therapy, hypofibrinogenemia, hyperfibrinogenaemia or lupus anticoagulant.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 25
Incorrect
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Which vitamin is found in NAD and NADP?
Your Answer:
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
- Physiology
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Question 26
Incorrect
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Which statement about antithrombin III is true?
Your Answer:
Correct Answer: It inhibits particularly factor II and X
Explanation:Antithrombin inactivates its physiological target enzymes, Thrombin (Factor II), Factor Xa and Factor IXa. ATIII binds to thrombin and then forms the thrombin-anti thrombin complex or TAT complex. This is a major natural pathway of anticoagulation. This binding of thrombin to AT is greatly enhanced in the presence of heparin.
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This question is part of the following fields:
- Haematology
- Physiology
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Question 27
Incorrect
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With regards to splenic micro-architecture which is not contained within the red pulp
Your Answer:
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
- Physiology
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Question 28
Incorrect
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Inactive cellular marrow is called
Your Answer:
Correct 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
- Physiology
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Question 29
Incorrect
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Vitamin K deficiency can be found in which of the following condition?
Your Answer:
Correct 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
- Physiology
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Question 30
Incorrect
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Which of the following factors is directly responsible for the breakdown of fibrinogen to fibrin?
Your Answer:
Correct Answer: Thrombin
Explanation:Prothrombin (coagulation factor II) is proteolytically cleaved to form thrombin in the coagulation cascade, the clotting process. Thrombin in turn acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalysing many other coagulation-related reactions.
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This question is part of the following fields:
- Haematology
- Physiology
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