1. The Cardiovascular System Chapter 13 By the end of today, you should be able to: Describe the 3 major elements of the cardiovascular system. Contrast the 2 “circuits” or “routes” that blood takes throughout the cardiovascular system. Relate the effects of activity/exercise to the cardiovascular system

2. The Closed Circulatory System Humans have a closed circulatory system (blood confined to vessels). The heart pumps blood into large vessels that branch into smaller ones leading into the organs. (arteries  arterioles  capillaries) Materials are exchanged by diffusion b/w blood and the fluid bathing the cells (interstitial fluid)

3. The Cardiovascular System Three Major Elements – Heart, Blood Vessels, & Blood 1. The Heart cardiac muscle tissue highly interconnected cells –4 chambers4 chambers Right atrium Right ventricle Left atrium Left ventricle

5. Circuits Pulmonary circuit –Sends oxygen-depleted (deoxygenated) blood to lungs to pick up oxygen & unload CO 2 Systemic circuit –Sends oxygen-rich (oxygenated) blood & nutrients to all body cells and remove wastes

6. The Cardiovascular System 2. Blood Vessels -A network of tubes –All blood vessels in body, joined end to end, would stretch 62,000 miles (2.5 times around the Earth) Arteries  arterioles Move blood away from the heart Elastic Fibers 3 layers (endothelial tissue, smooth muscle, connective tissue) Carries blood under relatively high pressure from heart to arterioles Largest artery = aorta (diameter of garden hose)

7. Blood Vessels Capillaries where gas exchange takes place Materials diffuse thru slits (openings) in capillary walls Single layer of epithelial tissue Connect arterioles to venules Serve the Respiratory System FYI-- (There is always 1/5 of our blood supply in the lungs)

8. Blood V essels Veins  Venules Move blood towards the heart 3 layers (similar to arteries except middle layer poorly developed) Carries blood under low pressure Many have valves that prevent backflow of blood Largest vein = inferior vena cava heart anatomy video model

10. The Cardiovascular System 3. The Blood RBCs (erythrocytes) WBCs (leukocytes) Platelets (thrombocytes) Plasma

11. Exercise CV System adapts to exercise Increase in heart pumping efficiency, blood volume, blood hemoglobin concentration, # of mitochondria in muscle fibers All of these improve oxygen delivery to and utilization by muscle tissue Good=Slow, steady buildup of exercise frequency & intensity Bad=suddenly shoveling snow, running 3 miles when body isn’t used to it

12. Inside the Human body video – 48 min Anatomy of the human body 1 Plastination, Heidelberg, Germany