BIOL 235 Chapter 21 Exam Questions and Answers 100% Pass

BIOL 235 Chapter 21 Exam Questions and Answers 100% Pass arteries - carry blood away from the heart, large and elastic arterioles - stem from arteries FUNCTION: regulate flow of blood into the capillary networks capillaries - as arterioles inter a tissue, they branch into capillaries most capillaries are continuous capillaries; plasma membrane of endothelial cells form continuous tube found in CNS, lungs, muscle tissue, skin FUNCTION: nutrient exchange between blood and interstitial fluid, blood to postcapillary venules venules - groups of capillaries within a tissue reunite and form venules 2 100% Pass Guarantee Katelyn Whitman, All Rights veins - blood vessels that convey blood from the tissues back to the heart have valves that prevent back flow of blood FUNCTION: blood back to heart, facilitate by valves in limbs tunica interna - endothelium layer forming innermost blood vessel and contacts the blood as it flows through the lumen basement membrane deep to the epithelium provides physical support internal elastic lamina is the outermost layer of the tunica interna and facilitates diffusion of materials tunica media - middle muscular and connective tissue layer, functions to regulate diameter of lumen through smooth muscle and elastic fibers external elastic lamina separates the tunica media from the interna externa vasoconstriction - narrowing of blood vessels caused by sympathetic stimulation 3 100% Pass Guarantee Katelyn Whitman, All Rights tunica externa - outer covering of a blood vessel consists of elastic and collagen fibers that supplies vessel wall with nerves and anchors vessels to surrounding tissues elastic arteries - largest in the body with thin vessel walls function as pressure reservoirs FUNCTION: conduct blood from heart to muscular arteries muscular arteries - medium-sized arteries, distribute blood to skeletal muscles and internal organs FUNCTION: distributing arteries collateral circulation - alternative route of blood flow to a body part through an anatomosis precapillary sphincters - at the metarte