REVIEWED PBSE QUESTIONS AND ANSWERS

REVIEWED PBSE QUESTIONS AND ANSWERS A normal arterio-venous oxygen difference is approximately what? a. 7mmHg b. 40mmHg c. 5 volumes percent d. 14 volumes percent - CORRECT ANSWER -5 volumes percent The effect of plasmin is to? a. limit clotting by splitting fibrin b. initiate the intrinsic pathway c. cleave thrombin d. activate the extrinsic pathway - CORRECT ANSWER -limit clotting by splitting fibrin Which clotting factor is activated by contact with foreign surfaces, roughened vascular walls, and platelet aggregation? a. V b. XII c. VIII d. X - CORRECT ANSWER -Factor XII (Factor XII is often called Hageman factor) The primary structural unit of proteins are? a. pyruvic acid b. conjugated fatty acids c. L-amino acids d. ribonucleic acids - CORRECT ANSWER -L-amino acids The main function of an enzyme is to do what? a. increases the rate of a biochemical reaction b. initiates a biochemical reaction c. acts as a substrate for a biochemical reaction d. alters the equilibrium of a biochemical reaction - CORRECT ANSWER -increase the rate of a biochemical reaction In 55% of patients, which coronary artery gives rise to blood supply for the SA node? a. right b. circumflex c. posterior descending d. obtuse marginal - CORRECT ANSWER -right Diagonal coronary arteries supply the : a. anterior wall of LV b. lateral wall of LV c. apex of LV d. free wall of the RV - CORRECT ANSWER -anterior wall of the LV (diagonals are branches of the LAD) The left anterior descending coronary artery arises from the left a. main coronary artery distal to circumflex b. main coronary artery distal to first diagonal c. main coronary artery d. coronary ostium - CORRECT ANSWER -main coronary artery If the diffusion coefficient for O2 is 1, the diffusion coefficient or CO2 is a. 20.3 b. 37.5 c. 0.81 d. 0.20 - CORRECT ANSWER -20.3 A characteristic of the oxygen dissociation curve for fetal hemoglobin is that a. its identical to adult curve b. it shifts to the right of maternal curve c. is unrelated to the maternal curve d. it shifts to the left of the maternal curve - CORRECT ANSWER -it shifts to the left of the maternal curve Which of the following is NOT done during resuscitation for CPB induced embolus? a. retrograde SVC perfusion b. carotid compression c. induction of barbiturate coma d. induction of hypotension - CORRECT ANSWER -induction of hypotension Which of the following is a reported disadvantage of cerebral saturation monitoring using NIRS a. globial ischemia events are not reflected in measurements b. pulsitile perfusion pressure is required for accurate measurement c. catheter placement is required for continuous measurement d. extra-cranial blood saturation is included in the measurement - CORRECT ANSWER -extracranial blood is included in the measurement Cephalosporins have little antimicrobial activity against a. pseudomonas aeruginosa b. pneumococci c. viridians streptococci d. staphylococcus aureus - CORRECT ANSWER -pseudomonas aeruginosa Persantine (dipyridamole) interferes with the function of a. platelets b. renin c. thromboxane A2 d. ADH - CORRECT ANSWER -platelets The classical pathway of complement activation is initiated by a. red blood cells b. antigen-antibody reactions c. cytotoxic T cells d. chemotaxis of white blood cells - CORRECT ANSWER -antigen-antibody reactions A conformational change of the platelet structure occurs when stimulated by exposure to foreign surfaces is best described as a. biconcave disc w/ multiple nuclei extensions b. discoid shape cell fragment c. globular form w/ pseudopedia d. large oval shaped cell w/ central nucleus - CORRECT ANSWER -globular form w/ pseudopodia During ECMO support, heparin requirements will increase a. when packed red cells are administered b. when platelets are administered c. when circuit flow is increased d. if patient is in renal failure - CORRECT ANSWER -when platelets are administered