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.
Arachnoid Mater. The arachnoid mater is the middle of three layers that make up the meninges, or membranes, that surround the spinal cord and brain. The dura mater is the outermost layer of the meninges. The innermost layer that contours closely to the many folds and crevices of the brain is called the pia mater.