Same chapter3 marksDifficulty: Medium
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Describe the cardiac cycle in outline and state its duration.
Original Khojo Papers practice question — not from a past board paper.
Answer
Atrial systole lasts about 0.1 s and pushes blood into the ventricles. Ventricular systole lasts about 0.3 s and pumps blood into the pulmonary artery and the aorta. Joint diastole lasts about 0.4 s, during which all the chambers relax and fill. The whole cycle takes about 0.8 s, giving about 72 beats a minute.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The heart sounds lub and dup are made by the closing of the atrioventricular and semilunar valves.
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