| List-I | List-II | ||
| A. | Tricuspid valves | I. | Guards the opening between right atrium and right ventricle |
| B. | Sino-atrial node | II. | Guards the opening between the left atrium and the left ventricle |
| C. | Mitral valves | III. | Guards the opening of right and left ventricles into pulmonary artery and aorta, respectively |
| D. | Semilunar valves | IV. | Cardiac musculature in the right upper corner of right atrium |
| 1. | Increased ventricular pressure causes closing of the semilunar valves. |
| 2. | The atrio-ventricular node (AVN) generates an action potential to stimulate atrial contraction. |
| 3. | The tricuspid and the bicuspid valves open due to the pressure exerted by the simultaneous contraction of the atria. |
| 4. | Blood moves freely from atrium to the ventricle during joint diastole. |
What would be the heart rate of a person if the cardiac output is 5L, blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL?
| 1. | 125 beats per minute | 2. | 50 beats per minute |
| 3. | 75 beats per minute | 4. | 100 beats per minute |
Doctors use a stethoscope to hear the sounds produced during each cardiac cycle. The second sound is heard when:
| 1. | AV valves open up |
| 2. | Ventricular walls vibrate due to the gushing of blood from the atria |
| 3. | Semi-lunar valves close down after the blood flows into vessels from the ventricles |
| 4. | AV node receives a signal from SA node |