PHYSIOL 335 Chapter Notes - Chapter 12: Tunica Externa, Varicose Veins, Tunica Media
Document Summary
Chapter 21: cardiovascular system: blood vessels and hemodynamics. Higher pressure: arterioles, capillaries (gas exchange, venules, veins. Blood vessels layers (tunics) deep to superficial: 1. Smooth muscle and/or elastic fibers lets you constrict or dilate vessels. Changes thickness in veins and arteries: 3. Elastic and collagen fibers: artery: thicker layers, especially smooth muscle, vein: thinner layers. Varicose veins: valves don"t work and blood pools: capillary walls are only one cell thick. Artery: transport blood away from heart, usually oxygenated blood, two types: Conducting arteries: conduct blood from heart to muscular arteries. Abundant elastic fibers in tunica media: walls stretch to accommodate surge of blood from ventricles. Distribution vessels: deliver blood to organs, diameter of pencil. Vasoconstriction: sympathetic innervation, adjust blood flow rate. Muscular arteries usually have dual blood supply going to muscle/tissue: dual blood supply = anastomosis, this is good because if there is a clot in one vessel, you have another.