| 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. |
Inadequate supply of oxygen to heart muscles leads to a symptom of acute chest pain. This disorder of the circulatory system is identified as:
| 1. | Angina pectoris | 2. | Cardiac arrest |
| 3. | Heart failure | 4. | Coronary Heart Disease |
| List-I | List-II | ||
| A. | P-wave | I. | Ventricular repolarization-relaxation phase |
| B. | P-R interval | II. | The onset of ventricular depolarization - leads to ventricular contraction |
| C. | QRS complex | III. | Time for the impulse to be conducted from SA node to the ventricles through the AV node |
| D. | T-wave | IV. | Atrial depolarization - leads to atrial contraction |