The blood vessels

The blood vascular system The heart The arteriesThe veins The capillaries pumps the blood carry oxygenated blood and nutrients to the tissues consists of a diffuse network of thin tubules through which gas exchange between blood and tissues takes place carry deoxygenated blood, rich in carbon dioxide and other metabolic products from the tissues to the heart

THE STRUCTURE OF THE ARTRIES AND VEINS  Composed of three layers: Tunica intima Tunica media Tunica adventitia

 Two components:  Squamous endothelial cells: Rest on a basal membrane (Basal lamina). Line the interior surface.  Sub endothelial layer: Loose connective tissue Smooth muscles arranged longitudinally. TUNICA INTIMA

TUNICA MEDIA  Smooth muscle cells.  Collagen and elastic fibers in-between.

TUNICA ADVENTITIA  Connective tissue rich in collagen and elastic fibers

 Tunica intima: Separated form tunica media by a layer of connective tissue called internal elastic lamina.  Tunica media: The thickest layer  Tunica adventitia: Rich in elastic fibers THE ARTERY T.S in Artery

Tunica intima: Does NOT have internal elastic lamina. Tunica media: The thinner layer Tunica adventitia: The Thickest layer Rich in collagen fibers. THE VEIN T.S in Vein

COMPARISON BETWEEN ARTERY AND VEIN