Vessel wall thinning

Capillary is the blood vessel with the smallest diameter and the widest distribution. They branch and kiss each other into a web. The density of capillary networks in various organs and tissues varies widely. Tissues and organs with strong metabolism, such as skeletal muscle, heart muscle, lungs, kidneys, and many glands, have dense capillary networks; tissues with lower metabolism, such as bone, Tendons and ligaments are sparse.