1. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Cardiovascular System  A closed system of the heart and blood vessels  The heart pumps blood  Blood vessels allow blood to circulate to all parts of the body  Functions of the cardiovascular system:  to deliver oxygen and nutrients to body cells  to remove carbon dioxide and other waste products from cells

2. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart  Location  Thorax between the lungs  Orientation  Pointed apex directed toward left hip  Base points toward right shoulder  About the size of your fist

3. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart Figure 11.1a–b

4. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart – Notes page 8 Figure 11.1c

5. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart – Notes page 8 Figure 11.2a

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Coverings  Pericardium—double-walled sac that encloses heart  Fibrous pericardium is loose and superficial  Serous pericardium is deep to the fibrous pericardium and composed of two layers:  Parietal pericardium  Outside layer that lines the inner surface of the fibrous pericardium  Visceral pericardium  Next to heart; also known as the epicardium  Serous fluid fills the space between the layers of pericardium

7. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Heart Wall Figure 11.2b

8. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Heart Wall  Three layers  Epicardium  Outside layer  This layer is the visceral pericardium  Connective tissue layer  Myocardium  Middle layer  Mostly cardiac muscle  Endocardium  Inner layer  Endothelium

9. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Heart Wall – Notes page 9 Figure 11.2c

10. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Chambers  Right and left side act as separate pumps  Four chambers  Atria  Receiving chambers  Right atrium  Left atrium  Ventricles  Discharging chambers  Right ventricle  Left ventricle

11. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Differences in Right and Left Ventricles Figure 11.4

12. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Septa  Interventricular septum  Separates the two ventricles  Interatrial septum  Separates the two atria

13. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Chambers page 9 Figure 11.2c

14. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Valves  Allow blood to flow in only one direction to prevent backflow  Four valves  Atrioventricular (AV) valves—between atria and ventricles  Bicuspid (AKA mitral) valve (left side of heart)  Tricuspid valve (right side of heart)  Semilunar valves—between ventricle and artery  Pulmonary semilunar valve  Aortic semilunar valve

15. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Valves Figure 11.2c

16. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart: Valves  AV valves  Anchored in place by chordae tendineae (“heart strings”)  Open during heart relaxation and closed during ventricular contraction  Semilunar valves  Closed during heart relaxation but open during ventricular contraction  Notice these valves operate opposite of one another to force a one-way path of blood through the heart

17. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 1 Blood returning to the atria, puts pressure against AV valves; the AV valves are forced open Ventricles Operation of the AV valves AV valves open (a) Notes page 11, Book page 367

18. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 2 Blood returning to the atria, puts pressure against AV valves; the AV valves are forced open As the ventricles fill, AV valve flaps hang limply into ventricles Ventricles Operation of the AV valves AV valves open (a)

19. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 3 Blood returning to the atria, puts pressure against AV valves; the AV valves are forced open As the ventricles fill, AV valve flaps hang limply into ventricles Atria contract, forcing additional blood into ventricles Ventricles Operation of the AV valves AV valves open (a)

20. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 4 Ventricles contract, forcing blood against AV valve flaps (a)

21. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 5 Ventricles contract, forcing blood against AV valve flaps AV valves close AV valves closed (a)

22. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5a, step 6 Ventricles contract, forcing blood against AV valve flaps AV valves close Chordae tendineae tighten, preventing valve flaps from everting into atria AV valves closed (a)

23. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5b, step 1 As ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open Aorta Pulmonary trunk Semilunar valve open Operation of the semilunar valves (b)

24. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.5b, step 2 As ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open Aorta Pulmonary trunk Semilunar valve open Semilunar valve closed As ventricles relax, and intraventricular pressure falls, blood flows back from arteries, filling the leaflets of semilunar valves and forcing them to close Operation of the semilunar valves (b) Notes page 12, Book page 367