MCQs Week 8 Loading... 1. Regarding anti-platelets Aspirin reversibly acetylates cyclo-oxygenase thus inhibiting the synthesis of thromboxane A2Ticlopidine is used less than clopidogrel as it is associated with a neutropenia in up to 5% of patientsTicagrelor is used as a secondary prophylaxis agent in TIA/CVAAspirin selectively inhibits the COX-1 enzyme Loading... 2. The following blood gas is most consistent with which situation? pH 7.56 pCO2 20mmHg pO2 100mmHg HCO3 25mmol/L SepsisEmphysemaProlonged vomitingTwo week residence at high altitude Loading... 3. All of the following are true of extensor pollicis longus EXCEPT It inserts at the base of the proximal phalanx of the thumbIt forms the ulnar side of the anatomical snuffboxIt's nerve supply is from the radial nerveIt's origin is from the posterior surface of the ulna and adjacent interosseous membrane Loading... 4. Regarding AIDs Homosexual and bisexual men compromise the most rapidly growing group of infected individualsAfter needle-stick injury with infected blood in health care workers there is a 3% seroconversion rate10% of AIDs cases worldwide are paediatric In Africa and parts of Asia the risk of female to male transmission is much higher than in the US Loading... 5. Which of the following is true regarding hypersensitivity reactions? Only exogenous antigens may elicit hypersensitivity reactionsThe development of hypersensitivity reactions is rarely genetically linkedSerum sickness is an example of a type III hypersensitivity reactionContact dermatitis is an example of a type I hypersensitivity reaction Loading... 6. Regarding adaptive immunity T-lymphocytes are responsible for defence against extracellular microbes and their toxinsB-lymphocytes develop into plasma cells to produce antibodiesMicrobial proteins directly activate CD4+ cellsStimulation of CD8+ cells results in activation of macrophages Loading... 7. Which of the following structures passes deep to the flexor retinaculum of the wrist? The palmar cutaneous branch of the ulnar nerveThe palmaris longus tendonThe flexor pollicis longus tendonThe ulnar artery Loading... 8. Which of the following statements about anticoagulants is INCORRECT? Fondaparinux is a safe alternative antithrombin agent in patients with HITWarfarin therapy can cause cutaneous necrosis in patients with a protein S deficiencyDabigatran is an example of a factor II inhibitorWarfarin blocks the gamma-carboxylation of glutamate residues in prothrombin and factors VII, IX, X and protein C/S Loading... 9. Regarding synovial flexor sheaths in the hand and wrist; which of the following is INCORRECT? It surrounds the flexor tendons in the carpal tunnelThe superficial and deep flexors are invested with a common synovial sheathFor the index, ring and middle finger a seperate synovial sheath lines the fibrous sheath over the phalangesThey are the origin of the palmar interossei Loading... 10. In the hand The superficial palmar arch is a direct continuation of the radial arteryPrinceps pollicis originates from the radial arteryEach digit is supplied by 2 arteriesThe lateral side of the dorsal venous network of the hand drains into the basilic vein Loading... 11. In considering drugs used in anaemias Ferrous sulfate 325mg contains more elemental iron than ferrous gluconate 325mgParenteral folic acid use is associated with venous thromboembolismThere is a risk of developing neurological damage in G-CSF use as it can mask an unrecognised B12 deficiencyChronic iron overload (haemachromatosis) can be efficiently treated with the iron chelators deferoxamine Loading... 12. Regarding the transport of oxygen in the blood The affinity of Hb for CO is 10 times its affinity for O2The p50 at altitude is decreasedWhen fully saturated each gram of normal heamoglobin in vivo contains about 1.34ml of O2A rising pH will shift the Hb02 dissociation curve to the right Loading... 13. Which of the following statements is correct? Ezetimibe is an example of a HMG-CoA reductase inhibitorGemfibrozil is a bile acid sequestrantNiacin is the only agent used in dyslipidaemias that does not cause hepatic toxicityStatins are associated with a lupus-like hypersensitivity disorder Loading... 14. The major mechanism for transporting CO2 in the blood is Carbamino compoundsDissolved in blood as per Henry's lawHaemoglobinBicarbonate Loading... 15. What is the value of pO2 in a subject living at sea level breathing air with a pCO2 of 32mmHg? 64mmHg90mmHg110mmHg120mmHg Loading... 16. Regarding the Direct Oral Anti-Coagulants (DOACs) Hirudin (leech saliva) has the same mechanism of action as apixabanRivoroxaban has a peak plasma level at 6 hoursDabigatran has an oral bioavailability of <10%Dabigatran has a half-life of 12-17hours and is dosed daily Loading... 17. In a compensated respiratory acidosis the most important buffer in terms of capacity is Plasma HCO3Intracellular proteinIntracellular phosphatePlasma protein Loading... 18. Which of the following drug-target pairing is INCORRECT? Aspirin - thromboxane A2Prasugrel - ADPAbciximab - GP IIb/IIIaDipyridamol - prostaglandin endoperoxidases Loading... 19. Heparin Slows the activity of antithrombin thus exerting it's anticoagulant effectHeparin use clinically is monitored by measuring the PTIs associated with osteoporosisHeparin-induced thrombocytopenia has significant morbidity and mortality from adverse bleeding events Loading... 20. All of the following shift the oxygen-haemoglobin dissociation curve to the right EXCEPT Reduced pHIncreased temperatureIncreased 2,3-BPGPresence of COHb Loading... 21. Consider the Bohr effect Deoxyhaemoglobin binds hydrogen more actively than oxyhaemoglobinIt causes a leftwards shift of the oxygen-haemoglobin dissociation curve It describes the effect of temperature on the oxygen-haemoglobin dissociation curveIt describes decreased oxygen binding by haemoglobin as red cells pass through the lung capillaries Loading... 22. Which of the following is the predominant cell type found in the para-follicular regions in lymph nodes and the peri-arteriolar sheaths in the spleen? ImmunoblastsB-lymphocytesT-lymphocytesMacrophages Loading...
