1. Chapter 12 Cardiovascular System

3. 1. Blood Vessels

5. All blood vessels are lined by a thin layer of tightly packed epithelial cells . Structural differences in the walls of the different kinds of blood vessels correlate with their different functions.

7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ed Reschke d. outer layer middle layer inner layer outer layer middle layer inner layer artery vein 20 µ m

9. Anatomy of a Capillary Bed blood flow arteriole capillaries arteriovenous shunt venule blood flow vein precapillary sphincters artery Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10. Blood Flow Through Capillary Beds Notice how small the capillaries are, just wide enough for one red cell

15. 2. the Heart

18. septum semilunar valve left atrium right atrium atrio ventricular (bicuspid) valve atrio ventricular (tricuspid) vave chordae tendineae tendons right ventricle left ventricle

19. Blood arrives first in the atrium then goes to the ventricule. The valves prevent the blood to go back to the previous chamber

22. 2. The systemic circuit carries blood between the heart and the rest of the body.

23. Blood rich in CO 2 , vessels are blue Blood rich in O 2 , vessels are red

27. The Pacemaker and the Control of Heart Rate The pacemaker sets the tempo of the heartbeat . It is composed of specialized muscle tissue in the wall of the right atrium.

28. The impulses sent by the pacemaker produce electrical currents that can be detected by electrodes placed on the skin. These are recorded in an electrocardiogram (ECG or EKG). An artificial pacemaker: is a medical device which uses electrical impulses, delivered by electrodes contracting the heart muscles, to regulate the beating of the heart.

33. 4. BLOOD

39. BLOOD TYPE

44. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fibrinogen Ca2 + 1. Blood vessel is punctured. 2. Platelets congregate and form a plug. 3. Platelets and damaged tissue cells release prothrombin activator, which initiates a cascade of enzymatic reactions. 4. Fibrin threads form and trap red blood cells. Blood-clotting process Prothrombin activator Prothrombin Thrombin Fibrin threads Ca2 +

47. 6.The Role of the Cardiovascular System in Homeostasis

49. What happens when this homeostasis is not maintained? Cardiovascular Disease Cardiovascular disease accounts for 40% of all deaths in the United States. The leading cause of death in the United States is heart attack.

51. fat coronary artery ulceration lumen of vessel cholesterol crystals atherosclerotic plaque Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Biophoto Associates/Photo Researchers, Inc.

54. D. HEART ATTACK When blood exits the heart, several coronary arteries immediately branch off to supply the heart muscle. If 1 or more of these arteries is blocked, the heart muscle cells will quickly die.