Blood Vessel Anatomy

Starter- write your answer! Explain how this patient’s cardiac output would be affected (if at all) by the electrical activity in their heart. Use the terms: starling’s law stroke volume cardiac output

• Loose connective tissue Internal elastic lamina Figure 11.9b  Structure of blood vessels. (b) The walls of arteries and veins are composed of three tunics: the tunica intima (endothelium underlain by a basement membrane), tunica media (smooth muscle and elastic fibers), and tunica externa (largely collagen fibers). Valve Tunica intima • Endothelium • Loose connective tissue Internal elastic lamina Tunica media External elastic lamina Tunica externa Lumen Venule Lumen Arteriole Artery Capillary network Vein Basement membrane Endothelium (b) Capillary

• Loose connective tissue Internal elastic lamina Figure 11.9b  Structure of blood vessels. (b) The walls of arteries and veins are composed of three tunics: the tunica intima (endothelium underlain by a basement membrane), tunica media (smooth muscle and elastic fibers), and tunica externa (largely collagen fibers). Valve Tunica intima • Endothelium • Loose connective tissue Internal elastic lamina Tunica media External elastic lamina Tunica externa Lumen Venule Lumen Arteriole Artery Capillary network Vein Basement membrane Endothelium (b) Capillary

Veins Veins have valves to prevent backflow of blood Prevent pooling Pooling can create a clot that can get stuck in the pulmonary artery (pulmonary embolism) Skeletal muscle contractions help venous return https://www.youtube.com/watch?v=49jUyBu4M1Q&list=LPW8ZlZW8ZoPE&index=1&feature=plcp

Vericose Veins Common in people who stand for long periods of time are obese or pregnant Occur when blood pools in the veins due to inactivity or low venous pressure https://www.youtube.com/watch?v=7Qs6iWSGzZE&feature=related start at 25 sec

Cover the section on arthrosclerosis and arteriolesclerosis (on study guide)

Capillary Beds (see fig. 11-11 in book) Precapillary sphincters- ring of smooth muscle, regulates blood flow through capillary beds When open blood flows into capillaries  diffusion occurs When closed blood flows from arteriole to venule  no diffusion occurs