Describe5 marksChallenge
The table below shows pressure changes in the left side of the heart (atrium, ventricle and aorta) during one cardiac cycle.
| Stage | Atrial pressure / mmHg | Left ventricular pressure / mmHg | Aortic pressure / mmHg |
|---|---|---|---|
| 1 (atrial systole) | 10 | 5 | 80 |
| 2 (ventricular systole begins) | 8 | 80 | 80 |
| 3 (ventricular systole peak) | 6 | 120 | 120 |
| 4 (ventricular diastole begins) | 4 | 90 | 100 |
| 5 (ventricular diastole, filling) | 8 | 0 | 90 |
Describe the changes in pressure shown in the table, and explain how these pressure differences cause the opening and closing of the atrioventricular (bicuspid) valve and the semilunar (aortic) valve.