Question

For each multiple choice question shade the letter of the alphabet of the appropriate answer on the scan sheet. Two marks will be given for a correct choice and zero mark will be given for an incorrect choice or no answer. 1. The force of cardiac contraction increases in response to a) an increased filling volume b) inhibition of cardiomyocyte L-Type (slow) Ca2 channels c activation of carotid baroreceptors d) activation of the myocardial muscarinic receptors e) Both a) and b) are correct 2. Digitalis toxin (a cardiac glycoside) a) inhibits the Na -K ATPase pump b) causes and increase in intracellula potassium ion levels c) promotes lusitrophy (diastolic relaxation) d) prevents sarcolemma membrane damage e causes blockage of the Na'- Ca2 exchanger 3. Pulmonary valve opens a when pressure in the pulmonary circulation exceeds pressure in the left atrium b) when pressure in the left ventricle exceeds pressure in the aorta c) when pulse pressure increases d) when pressure in the right ventricle exceeds pressure in the pulmonary arteries c during a diastolic phase of the cardiac cycle In a 2-lead ECG trace 4. a) the duration of the R-R interval increases during exercise as compared to at rest b) a flattened P waves is associated with hypokalemia c) elevation of a ST-segment is associated with myocardial infarction d) inverted T-wave is associated with myocardial ischaemia e) Both c) and d) are correct 5. A decrease in total peripheral vascular systemic resistance (TPR) is a result of a) increased endothelial nitric oxide c) inhibition of histamine release d) All of the above are correct Only a) and c) are correct e) 6. Blood capillaries a) are major resistance vessels b) are sites of exchange between the blood and body cells c) temporarily expand and hold blood ejected during systole to ensure continuous flow of blood to the tissues d) have large radii when compared to veins e) hold approximately 60% of the blood volume of the body at rest

Answer 1

1 the force of cardiac contraction in response to an increased filling volume

2 Digital toxin inhibits Na K ATPase pump

3 pulmonary valve opens when pressure in the right ventricle exceeds pressure in pulmonary arteries

4 In a 2 lead both c and d are true

ST elevation is seen in myocardial infarction

T wave inversion is myocardial ischaemia

5 increased endothelial nitric oxide ( vasodialtor)

6 Blood capillaries are site of exchange between blood and body cells