1. The Cardiovascular System The Heart 20-1

2. FUNCTIONS OF THE HEART Generating blood pressure Routing blood Heart separates pulmonary and systemic circulations Ensuring one-way blood flow Heart valves ensure one-way flow Regulating blood supply Changes in contraction rate and force match blood delivery to changing metabolic needs 20-2

3. SIZE, SHAPE, LOCATION OF THE HEART Size of a closed fist Shape Apex: Blunt rounded point of cone Base: Flat part at opposite of end of cone Located in thoracic cavity 20-3

4. HEART CROSS SECTION 20-4

5. HEART WALL Three layers of tissue Epicardium: This serous membrane of smooth outer surface of heart Myocardium: Middle layer composed of cardiac muscle cell and responsibility for heart contracting Endocardium: Smooth inner surface of heart chambers 20-5

6. HEART WALL LAYERS 20-6

7. HEART WALL LAYERS 20-7

8. EXTERNAL ANATOMY Four chambers 2 atria 2 ventricles Auricles a small, muscular pouch at the upper corner of the atrium Major veins Superior vena cava Pulmonary veins Major arteries Aorta Pulmonary trunk 20-8

9. EXTERNAL ANATOMY 20-9

10. HEART VALVES Atrioventricular Tricuspid Bicuspid or mitral Semilunar Aortic Pulmonary Prevent blood from flowing back 20-10

11. HEART VALVES 20-11

12. FUNCTION OF THE HEART VALVES 20-12

13. BLOOD FLOW THROUGH HEART 20-13

14. INTERACTIVE HEART Go to: http://www.innerbody.com/image_card02/card51-new.html And use the inteactive explorer to practice your knowledge of the heart.