Question

please do not exceed 12 sentences for the following question.

Question: Define stroke volume. Then give a detailed explanation of the intrinsic and extrinsic controls over stroke volume. Thanks.

Answer 1

Stroke volume - it is the amount of blood pumped by each ventricle per beat is called stroke volume.

Normal stroke volume - 80 ml.

Control of stroke volume or intrinsic auto regulation-

This is done by two types -

1. Heterometric Regulation - The myocardial contractility depends on pre-load and after-load.

2. Homometric regulation - The myocardial contractility independent of initial length of cardiac muscle.

Control of heart rate or extrinsic auto regulation -

This by cardiac innervations by vaso motor centre VMC and Cardiac vagal centre CVC.