ANATOMY

Detailed explanation-1: -The average stroke volume of a 70 kg male is 70 mL Not all of the blood that fills the heart by the end of diastole (end-diastolic volume-EDV) can be ejected from the heart during systole. Thus the volume left in the heart at the end of systole is the end-systolic volume (ESV).

Detailed explanation-2: -Cardiac output in humans is generally 5-6 L/min in an at-rest to more than 35 L/min in elite athletes during exercise. HR is determined by signals from the sinoatrial node, which automatically depolarizes at an intrinsic rate of 60 to 100 times each minute.

Detailed explanation-3: -Your stroke volume is the amount of blood your heart pumps each time it beats, and your heart rate is the number of times your heart beats per minute. During exercise, your body may need three or four times your normal cardiac output, because your muscles need more oxygen when you exert yourself.