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.
The structure of the vessels have distinguishing features from arterial side to venous side (primarily muscle type or lack of muscle). The 5 different types of vessels have a different design of these 3 layers: 1) Tunica Interna (intima) - the inner lining of a blood vessel that is in contact with the blood. It's composed of simple squamous epithelium known as endothelium. There's also a basement membrane which is the vessels guide to repair, helps set-up for repair. The internal elastic lamina has window like openings that help allow things to diffuse out of the blood.