Question

How do arteries maintain blood pressure even when the heart isn't pumping out blood during diastole?

Answer 1

Diastole is when the heart relaxes prior to contraction and the arterial pressure drops since there is sudden flow of blood from the arterial compartment into the tissue capillaries. Diastolic pressure is the lowest arterial pressure during left ventricular diastole. The factors which controls the rate of drop of arterial pressure are:

• Terminal arteriole resistance usually at the junction of artery to the capillaries which in turn meter the rate of outflow of blood from the arteries.
• Another factor which influence the arterial pressure is the interbeat interval which is defined as the time interval between contractions of the left ventricle and the heart rate. Increasing HR would also increase the diastolic pressure apparently when there is constant arteriole resistance because of the lesser time available for the blood to leave the arterial compartment.
• Third is the rebound of the conduit arteries. Diastolic arterial pressure is sustained by the windkessel energy.