Afterload is best determined by?
Ans. c (Peripheral resistance). (Ref.; Gangong, Physiology, 22 nd/pg.p 572)PRE-LOAD AND AFTER-LOAD# After-load is the pressure in the arteries against which the ventricle pumps out the blood.- After-load = diastolic arterial pressure (proportional to peripheral resistance).- Vasodilators (e.g., hydralazine) decrease after-load.# The degree of filling of ventricles is pre-load.- Pre-load pumps up the heart.- Pre-load = ventricular end-diastolic volume- Venous dilators (e.g., nitroglycerin) decrease pre-load.- Pre-load increases with exercise (slightly) and with increase in the blood volume (overtransfusion) and excitement (sympathetics).
Heart, Circulation, and Blood
End diastolic volume
End systolic volume
Peripheral resistance
Compliance
Peripheral resistance