important role is to regulate the movement of materials into and out of cells. The phospholipid bilayer structure (fluid mosaic model) with specific membrane. proteins accounts for the selective permeability of the membrane and passive. and active transport mechanisms.
Structure of Blood Vessels a) Three distinct layers or tunics form the walls of blood vessels: ---The tunica interna (tunica intima) is the innermost layer.It contains the endothelium which is a continuation of the endocardial lining of the heart.tructure of Blood Vessels a) Three distinct layers or tunics form the walls of blood vessels: ---The tunica interna (tunica intima) is the innermost layer.
In arteries the outer margin of the tunica intima cointains a thick layer of elastic fibers called the internal elastic membrane.       2.Tunica media (Latin for middle coat) is the middle layer. Contains concentric sheets of smooth muscle tissue in a framework of loose connective tissue.he tunic intima is the innermost layer of a blood vessel. It has a slic surface that minimizes friction, allowing blood to move through the lumen. 1 person found this useful. Edit. Share to: Answered.