1. Circulatory System Professor Andrea Garrison Biology 11 Illustrations ©2010 Pearson Education, Inc. unless otherwise noted Circulatory System1

2. Circulatory system = Cardiovascular system = heart, blood vessels & blood Circulatory System2

3. Function = homeostasis – Transport O 2 /CO 2 Food/wastes Fluids Hormones – Regulate pH Water balance Temperature – Immune defense Circulatory System3

4. Blood ~ 5 liters in adult – Plasma – Cellular elements Circulatory System4

5. Blood Plasma – ~ 55% of blood volume – 90% water – 10% solutes Blood proteins Nutrients Wastes Gases Hormones Circulatory System5

6. Blood Cellular elements – ~ 45% of blood volume Circulatory System6

7. Blood Red blood cells – 5 million/cc (=ml) – Carry O 2 – Produced in bone marrow – Biconcave – No nucleus – Live ~ 120 days Circulatory System7

8. Blood White blood cells – 4,000 – 11,000/cc – Protection from disease – Produced in bone marrow – Have nucleus – Long-lived Circulatory System8

9. Blood Platelets – 200,000 – 400,000/cc – Form blood clots – Produced in bone marrow – Cell fragments Circulatory System9

10. Heart Pumps blood to body’s cells Circulatory System National Heart Lung Blood Institute, www.nhlbi.nih.gov 10

11. Heart Anatomy Circulatory System; From Wikimedia Commons, Diagram of the human heart, created by Wapcaplet in Sodipodi. Cropped by Yaddah to remove white space (this cropping is not the same as Wapcaplet's original crop).WapcapletYaddah 11

12. Heart Anatomy 4 chambers – 2 atria – 2 ventricles Valves – Atrioventricular (AV) valves – Semilunar valves Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 12 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

13. Heart Anatomy 4 chambers – 2 atria Receive blood – 2 ventricles Pump blood out of heart Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 13 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

14. Heart Anatomy Valves – Prevent backwards flow of blood Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 14 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

15. Heart – Double Circuit Circulatory System15

16. Blood Vessels Arteries carry blood away from heart Veins return blood to heart Capillaries in between – Every organ has its own capillary network Circulatory System16

17. Blood Vessels Circulatory System17

18. Blood Vessels Capillaries – Gas and nutrient exchange – Very small vessels – Walls one cell thick Effective diffusion – Narrow lumen One cell at a time Effective diffusion Circulatory System18

19. Blood Vessels Capillaries – Gas and nutrient exchange – Very small vessels – Walls one cell thick Effective diffusion – Narrow lumen One cell at a time Effective diffusion Circulatory System19

20. Blood Circuit artery arteriole heart capillaries vein venule Circulatory System20

21. Double Circuit Circulatory System21

22. Heart Anatomy Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 22 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

23. Blood Flow through the Heart Circulatory System23

24. Blood Flow through Heart Circulatory System24

25. Blood Flow through Heart Circulatory System25

26. Blood Flow through Heart Circulatory System26

27. Blood Flow through Heart Circulatory System27

28. Blood Flow through Heart Circulatory System28

29. Blood Flow through Heart Circulatory System29

30. Blood Flow through Heart Circulatory System30

31. Blood Flow through Heart Circulatory System31

32. Blood Flow through Heart Circulatory System32

33. Blood Flow through Heart Circulatory System33

34. Blood Flow through Heart Circulatory System34

35. Heartbeat Intrinsic to heart muscle Regulated by sinoatrial node (pacemaker) – Its own intrinsic rate of beating – Sends electric impulses so all cells beat w/it – Involuntary nervous system ↑ or ↓ heart rate Circulatory System35

36. Heartbeat Circulatory System36

37. Heartbeat Circulatory System37

38. Heart Rate Resting heart rate 60-100 bpm (~ 72 bpm healthy non-athlete) Heart alternates between contraction and relaxation – Contraction = systole – Relaxation = diastole Circulatory System38

39. Cardiac Cycle Circulatory System39

40. Cardiac Cycle Circulatory System40

41. Cardiac Cycle Circulatory System41

42. Heart Valves Open when P behind > P in front Close when P in front > P behind Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 42 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

43. Heart Valves Healthy valves insure one-way flow – Tendons attach AV valves to ventricle wall – Semilunar valves have little pressure in front Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 43 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

44. Heart Valves Damaged valves – Allow backflow – Cause heart murmur Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 44 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

45. Heart Valves Make heart sounds when they close – Healthy sounds – Heart murmur Circulatory System; modified from National Cancer Institute, NIH, www.cancer.gov 45 Right AV valve Left AV valve Right semilunar valve Left semilunar valve

46. Blood Flow through Vessels Systole – Ventricles contract – Blood leaves heart via arteries – Arterial pressure ↑ Diastole – Ventricles relax – Arterial pressure ↓ Blood flow surges in arteries Circulatory System46

47. Blood Flow through Vessels Side note: – Blood pressure Systolic pressure during systole Diastolic pressure during diastole Systolic P/diastolic P – Average <120/<80 – High 140/90 or greater Circulatory System47

48. Blood Flow through Vessels Surging and pressure ↓ with distance from heart No difference in pressure in capillaries and veins during systole and diastole Blood flow smooth in capillaries and veins Circulatory System48

49. Blood Flow through Vessels Blood pressure lowest in veins Heartbeat cannot return blood to the heart Venous return depends on other mechanisms – Skeletal milking – Respiratory pumping Circulatory System49

50. Return of Blood through Veins Skeletal milking – Functions in arms and legs – Muscle contraction around veins squeezes blood towards heart – Veins have one-way valves – Blood is “milked” towards torso Circulatory System50

51. Return of Blood through Veins Respiratory pumping – Inhalation decreases pressure around heart Sucks blood through abdominal and chest cavities toward heart Circulatory System51

52. Return of Blood through Veins Respiratory pumping – Inhalation decreases pressure around heart Sucks blood through abdominal and chest cavities toward heart Circulatory System52

53. Vasodilation/Vasoconstriction Blood vessels can dilate or constrict – Involuntary nervous system Controls blood pressure Fight or flight response – Local tissue control Constrict to ↓ blood flow – in cold weather to avoid heat loss Dilate to ↑ blood flow – in warm weather to cool off – For healing of injured tissues Circulatory System53

54. Cardiovascular Disease Diseases of the heart and blood vessels Kill over 1 million people in US each year Circulatory System54

55. Atherosclerosis Circulatory System55

56. Coronary Artery Disease Circulatory System56

57. Cerebral Vascular Disease Stroke – Blockage of blood vessel in brain Blood clot or fatty deposits – Bleeding blood vessel in brain Rupture due to weak vessel wall or high blood pressure Circulatory System57

58. Peripheral Artery Disease Blockage of blood vessels in legs – ↓ blood flow to legs and feet – Pain in legs when walking – Greater risk of heart attack/stroke Circulatory System58

59. Hypertension High blood pressure – Can harden arteries ↓ blood flow to heart – Chest pain – Heart failure—inability of heart to pump enough blood to organs Can rupture blood vessels – Stroke – Kidney damage Circulatory System59

60. Heart Health Don’t smoke Exercise regularly Maintain a healthy weight Healthy diet – Low in saturated fats – No trans fats – Low cholesterol – Low sodium – High fiber (lowers cholesterol) Circulatory System60