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.
Its called tunica intima The tunica media is the middle layer in a blood vessel wall and is composed predominantly of smooth muscle reinforced by organised layers of elastic tissue which form elastic laminae.onfidence votes 2. The three layers of the arterial wall are, from outside to inside, the adventia, the media and the intima. A flat layer of cells, called endothelial cells, forms a boundary between the blood in the lumen, or cavity, and the innermost layer of the arterial wall.