Blood Physiology and Hematology Basics MCQs

Physiology · 32 free questions with answers & explanations.

1. The oxygen-hemoglobin dissociation curve shifts to the right (decreased oxygen affinity) in which of the following conditions?
2. Plasma oncotic pressure (colloid osmotic pressure) is primarily maintained by:
3. Plasma oncotic pressure is principally generated by albumin. A patient with chronic liver disease has serum albumin of 1.8 g/dL (normal 3.5–5.0 g/dL). Using the Starling forces concept, explain the predominant mechanism of ascites in this patient.
4. An athlete's complete blood count shows: Hb 17 g/dL, Hct 50%, RBC 5.8 × 10⁶/µL. Mean corpuscular volume (MCV) calculation yields 86 fL. Which of the following correctly interprets this blood picture?
5. Platelet activation following vascular injury involves multiple amplification steps. Thromboxane A2 (TXA2) amplifies platelet activation by binding the TP receptor. Which intracellular pathway does TP receptor activation utilise, and which is its primary effect on platelets?
6. Erythropoietin (EPO) produced by peritubular fibroblasts of the renal cortex stimulates erythropoiesis by which receptor signalling mechanism?
7. G6PD (glucose-6-phosphate dehydrogenase) deficiency renders erythrocytes vulnerable to oxidative haemolysis. The key mechanism is the depletion of which molecule that normally protects against oxidative stress?
8. The intrinsic pathway of coagulation is initiated by factor XII (Hageman factor) contact activation on negatively charged surfaces. What is the physiological relevance of this pathway in vivo?
9. Erythropoietin (EPO) production in response to hypoxia is mediated by which transcription factor that is stabilised under low O2 conditions?
10. Erythropoietin (EPO) receptor signaling uses the JAK-STAT pathway. Which specific Janus kinase and STAT mediates EPO's antiapoptotic and proliferative effects in erythroid progenitors?
11. The Donnan effect across the red blood cell membrane contributes to the 'chloride shift' during CO₂ transport. Which protein mediates this anion exchange and what is its clinical relevance in band 3 deficiency?
12. The complement system can be activated via three pathways. The membrane attack complex (MAC) is assembled by the terminal complement components. Paroxysmal nocturnal hemoglobinuria (PNH) occurs due to somatic mutation in PIG-A gene, leading to deficiency of GPI-anchored proteins. The two GPI-anchored complement regulatory proteins whose absence leads to hemolysis in PNH are:
13. Erythropoietin (EPO) is produced primarily by peritubular interstitial cells in the renal cortex and outer medulla in response to hypoxia. The molecular mechanism by which renal hypoxia triggers EPO gene transcription involves:
14. The erythrocyte band 3 protein (AE1, anion exchanger 1) performs two critical functions: chloride-bicarbonate exchange (for CO₂ transport) and structural anchoring of the spectrin-actin cytoskeleton. Hereditary spherocytosis most commonly involves mutations affecting which component of the vertical linkage between band 3 and spectrin?
15. The oxygen dissociation curve of hemoglobin shows a sigmoidal shape reflecting cooperative binding. The Hill coefficient (n) of hemoglobin is approximately 2.8 (theoretical maximum for 4 subunits is 4). A Hill coefficient close to 1 would indicate what change in hemoglobin behavior?
16. The erythrocyte membrane maintains its biconcave disc shape through a spectrin–actin cytoskeletal network. Ankyrin links spectrin to which integral membrane protein, and how does this anchorage maintain cell deformability?
17. Thrombopoietin (TPO) is the primary regulator of platelet production. Where is TPO predominantly synthesized, and how does the circulating platelet mass regulate TPO levels?
18. The thrombopoietin (TPO)-thrombopoietin receptor (MPL/c-Mpl) signaling pathway regulates megakaryopoiesis and platelet production. A unique feature of TPO regulation is:
19. In sickle cell disease, a patient with acute painful vaso-occlusive crisis develops sudden severe anemia with reticulocytopenia and a spleen larger than the baseline. The most likely diagnosis is:
20. A patient with sickle cell disease is started on hydroxyurea. The mechanism by which hydroxyurea reduces sickling crises is:
21. A patient with microangiopathic haemolytic anaemia has elevated LDH, low haptoglobin and haemoglobinuria. The haemoglobinuria indicates which pathological level of haemolysis?
22. Erythropoietin (EPO) is produced primarily in the kidney in response to tissue hypoxia. The cellular mechanism linking hypoxia to EPO gene transcription involves:
23. A transfusion medicine specialist uses the zeta potential concept to understand RBC aggregation. Which property of normal RBCs prevents spontaneous agglutination in vivo?
24. A 50-year-old man at rest has a hemoglobin of 15 g/dL, PaO2 of 98 mmHg, and SaO2 of 98%. His cardiac output is 5 L/min. Calculate his oxygen delivery (DO2) in mL/min. (O2 binding capacity of hemoglobin = 1.34 mL O2/g Hb; ignore dissolved O2)
25. A high-altitude acclimatized mountaineer (at 5500 m for 3 weeks) has elevated 2,3-BPG in erythrocytes. What is the physiological consequence of elevated 2,3-BPG on hemoglobin function, and how does this aid O2 delivery at altitude?
26. In polycythaemia vera (PV), there is a JAK2 V617F mutation causing erythrocytosis. Patients with PV characteristically have low serum erythropoietin (EPO) levels. What is the physiological mechanism explaining the EPO suppression?
27. Erythropoietin (EPO) is primarily produced in the kidney in response to hypoxia. The intracellular mechanism by which hypoxia triggers EPO gene transcription is:
28. Erythropoietin (EPO) is secreted primarily by the peritubular interstitial cells of the renal cortex. Its production is stimulated by hypoxia through which transcription factor pathway?
29. A patient with acquired hemophilia A has a prolonged aPTT that does NOT correct with a 1:1 mix of patient plasma with normal plasma. What does failure to correct in the mixing study indicate?
30. Erythropoietin (EPO) is produced primarily by which cells, and what is the primary stimulus for its production?
31. During hemostasis, thrombin plays a central amplifying role. Which action of thrombin is responsible for AMPLIFYING the coagulation cascade rather than just converting fibrinogen to fibrin?
32. Erythropoietin (EPO) is produced by peritubular interstitial cells of the kidney in response to hypoxia. The HIF (Hypoxia Inducible Factor) pathway that mediates EPO gene transcription involves: