Question

Define the component layers of large artery and large vien including details of the cells and matrix of the layers and their associated mechanical properties(E values).

Medical related

Answer 1

Arteries and veins are comprised of three layers namely tunica intima, tunica media and tunica externa.

Tunica Intima - It form the inner layer of arteries and vein and is the thinnest layer, which is composed of a single layer of endothelial cells which is arranged continuously and supported by a sub-endothelial layer of connective tissue and supportive cells. This ultra-thin design of tunica intima facilitate the exchange of gases and nutrients through the capillary walls. A thin membrane comprises of elastic fibers that run parallel to the vessel surround the tunica intima.

Tunica Media - As the name suggest this layer is place between tunica intima and tunica extrena and composed of smooth muscle cells and connective and elastic tissues which are arranged circularly around the vessel. As compared to vein this layer is thicker in arteries. A large amount of smooth muscle present in tunica media of arterioles make them key regulator of blood flow between arteries and capillaries. This allow efficient exchange of gas and nutrition.

Tunica Externa - It is the outermost layer of arteries and veins and comprised entirely of connective fiber and an external elastic lamina surround it. The work of lamina is to anchor vessel with surrounding tissues. Veins are located superficially on the skin and possess higher chance of getting damage so in veins this layer is thicker to provide protection and prevent the collapse of blood vessel.