Ch 11 Blood Vessels (PPT 1) Did you know?... 60,000 miles of vessels carry blood to all body cells!

Introduction 5 vessels = carry blood from heart body cells heart arteries arterioles capillaries venules veins capillaries

Arteries Carry blood away from the heart Usually carry oxygenated blood 3 layers: 1.Tunica Interna 2.Tunica Media 3.Tunica Externa

Arterioles Carry blood away from the heart “little arteries” Similar 3 layers to arteries, but smaller

Capillaries One layer thick = Simple squamous epithelium Diffusion with body cells (including lungs)

Venules Carries blood towards heart “little veins” Similar 3 layers to veins, but smaller

Veins Carries blood towards the heart 3 layers: 1.Tunica Interna 2.Tunica Media 3.Tunica Externa Usually carry deoxygenated blood

3 layers of vessels (except capillaries) Tunica externa (adventitia)- outermost layer, loose connective tissue Tunica media- middle layer, smooth muscle Tunica Interna- innermost layer, endothelial cells Lumen- hollow center of vessel

Differences Valves are in veins only Larger lumen in veins More elastic connective tissue in arteries Thicker tunica media in arteries

Factors affecting Venous Blood Flow Valves Milking action of skeletal muscle Breathing “Respiratory Pump” Small amount of smooth muscle in vessel wall

FYI- Circulation Arteries and veins in same place are usually side by side carrying blood in opposite directions and have the same names: Ex. Pulmonary artery and pulmonary vein But sometimes… arteries and veins do not have same names: Ex. Carotid artery and jugular vein Abdominal aorta and inferior vena cava

Pulmonary Circulation General pulmonary circulation loop: From heart to lungs, then back to heart

Systemic Circulation General systemic circulation loop: From heart to cells of the body, then back to heart FYI: Arteries and veins of systemic circulation are usually named for the body regions we learned in chapter 1 (ex. brachial, ulnar, femoral)

Systemic Circulation Arteries branching off of aorta to body cells Notice which branches from which

Systemic Circulation Arteries branching off of aorta to body cells Notice which branches from which

Systemic Circulation Veins leading to IVC and SVC from body cells Notice which leads to which

Systemic Circulation Veins leading to IVC and SVC from body cells Notice which leads to which

Arteries and veins side by side

Hepatic portal part of systemic circulation Hepatic vein