Question

Explain how changes in the physical and anatomic properties of blood vessels as you move from the large arteries to the microcirculation and the venous system affect the pressure, flow velocity and pulse wave b)

Answer 1

As we move from arteries to veins,antomical changes are;

Arteries carries blood away from the heart to the tissues,whereas veins carries blood to the heart from tissues.

Veins have thinner walls as compared to arteries.

Veins are less muscular whereas arteries are more muscular.

It is the tunica media the smooth muscle layer which is thick in arteries and thin in veins.

Microcirculation means capillaries,they are very thin,they have a lining of squamous epithelium.The pressure which works here are hydrostatic pressure,colloidal osmostic pressure etc.

At the middke of capillaries,pressure is zero,at arterial end hydrostatic pressure is high while at venous end it is low.Colloidal osmotic pressure remains steady.

Pressure is more in arterial system and less in venous system.

Velocity of blood is affected by pressure,increasing pressure decrease blood flow,whereas in veins increasin pressure increases blood flow.

Pulse wave is sharp in arteries and not felt in veins.It is due to action of heart.When heart contract and eject blood in the arteries, it eject blood with a high pressure,it is the this wave of pressure which we feel as pulse.