Question

- What purpose/benefit does an elastic aorta have in terms of the change in the flow rate?

Answer 1

The aorta is the most proximal artery connected directly to the heart and acts both as a conduit and an elastic chamber. In its latter role, the aorta's elasticity serves to convert the heart's pulsatile flow to nearly steady flow in peripheral vessels.

The aorta serves as an elastic reservoir, which distends with blood during the heart's contraction and discharges blood through the peripheral resistance by elastic recoil while the heart refills. This accounts for the smoothing action of the aorta in converting the pulsatile flow of the heart to smooth flow in blood vessels.

At the end of ventricular ejection, the pressure in the aorta falls much more slowly than in the left ventricle because the large central arteries, and particularly the aorta, are elastic and thus act as a reservoir during systole, storing some of the ejected blood, which is then forced out into the peripheral vessels during diastole (Windkessel effect). Then the pressure pulse generated by ventricular contraction travels along the aorta as a wave . This phenomenon, known as the windkessel effect, helps to decrease the load on the heart and to minimize the systolic flow and maximize diastolic flow in the arterioles

By this mechanism The elasticity of Aorta Helps to maintain A constant Flow rate During both systole and diastole of the Heart.