CCI practice exam Questions with well explained answers

The second heart sound is caused by closure of what two valves? - Answer-Aortic and pulmonic What phase of the cardiac cycle immediately follows closure of the semilunar valves and precedes the opening of the AV valves? - Answer-Isometric relaxation What percentage of ventricular filling normally results from atrial contraction? - Answer-15-20% Peripheral venous pressure is the same as what pressure? - Answer-Right atrial Which hemodynamic measurement most directly reflects left ventricular afterload? - Answer-Mean BP In a normal patient with a fixed cardiac output the mean arterial blood pressure is determined cheifly by? - Answer-Afterload The rate induced regulation of the force of contraction, sometimes called the staircase, treppe, or bowdich effect is? - Answer-Rapid HR increases the force of contraction Which class of vessels has the capacity to store the largest volume of blood? - Answer-Systemic veins Closure of the semilunar heart valves is associated with a hemodynamic what? - Answer-Diacrotic notch Central venous pressure is the same as what other pressure? - Answer-Right atrial The amount of blood pumped from each ventricle during a single systole is the? - Answer-Stroke volume The naturally occurring neurotransmitter liberated at the parasympathetic nerve junction is? - AnswerAcetylcholineWhat is the primary effect of vagal nerve stimulation on the heart? - Answer-Decreases automaticity Baro-Receptors in the aortic arch are termed? - Answer-Stretch receptors Mild depression in ventilation results in? - Answer-Positive chronotropism What is the baseline trasmembrane voltage inside the resting cardiac muscle cell? - Answer--90 MV Which portion of the EKG represents the time when both atria depolarize? - Answer-P wave What is the velocity of electrical conduction through the AV node? - Answer-0.02-0.1 M/sec