Assume that for one beat, the stroke volume of the left ventricle is greater than that of the right ventricle. Explain why in a normal heart this would be corrected on the next beat.

Stroke volume is the volume of blood pumped by heart's left ventricle in one contraction. Two third of the blood is pumped out by left ventricle to the aorta from where it is supplied to the rest of the body. After circulating in body, the same volume of blood returns to the right ventricle from where it is pumped to lungs for reoxygenation. Hence, stroke volume is same for left and right ventricle.

If for some reason stroke volume of the left ventricle became greater than the right ventricle it means that more blood was pumped from the heart to body. This will be corrected in next beat because this same volume of blood will return to the right ventricle and so now the left and right ventricle will pump equal volumes again. There will be loss or gain of blood.  

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