BIOC34H3 Lecture Notes - Lecture 6: Stroke Volume, Afterload, Cardiac Muscle
Document Summary
Lecture 6: stroke volume regulation (continued: regulation of end diastolic volume. End diastolic volume is the ventricular volume at the end of diastole - when the ventricular volume is at its greatest level. Technically, pre-load is the degree of stretching of the ventricles at the end of diastole. From a practical point-of-view, the easiest way to think of pre-load is to think of it as the end diastolic pressure (edp) in the ventricles. The effect of pre-load on stroke volume is relatively simple: if you increase the pressure of blood in the atria and then the ventricles, the volume of blood within the ventricle (edv) is going to increase. This initial pressure (within the ventricles; prior to contraction) is referred to as preload. The ventricular pressure-volume loop below illustrates the effects of reducing pre-load (end-diastolic pressure) on end-diastolic volume (edv) and therefore on stroke volume (sv).
