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.
Brain and spinal cord are surrounded by membranes called the meninges. There are three layers - outermost dura mater, middle arachnoid and the inner pia mater. The space between the arachnoid and pia mater is filled with the cerebrospinal fluid (CSF). It acts as a shock absorber. An infection of the meninges is called meningitis.