Question

Define cardiac output and explain how it is increased during exercise.

Answer 1

Cardiac output is the amount of blood pumped by heart in one minute. The cardiac output can be determined by the heart rate and the amount of blood pumped out by left ventricle in one contraction. The normal range of the cardiac output in healthy heart is 4.7 liter of blood /minute.

During exercise, muscle needs to more oxygen to work out.Therefore, heart beats per minute increases to pump more blood to reach to the muscles to deliver oxygen into it.The stroke volume also increases to fill up the left ventricle before it pumps.So, the increasing the stroke volume and heart rate causes increases in cardaic output.Increased cardiac output is required during exercise to keep blood pressure maintained to supply the oxygenated blood to brain and vital organs.