Cardiovascular I

1. Cardiovascular I

2. Overview • General Introduction/Function • Red Blood Cells • Hemoglobin • Hematopoiesis • Heart Anatomy • Skeletal versus Cardiac Muscle • Electrical conduction in the heart

3. Composition of Blood • Blood is the body’s only fluid tissue • Formed elements: • Hematocrit

4. Composition of Blood Figure 18.1

5. Protection • Blood prevents blood loss by: • Activating plasma proteins and platelets • Initiating clot formation when a vessel is broken • Blood prevents infection by: • Synthesizing and utilizing antibodies • Activating complement proteins • Activating WBCs to defend the body against foreign invaders

6. Formed Elements • Erythrocytes, leukocytes, and platelets make up the formed elements • Most formed elements survive in the bloodstream for only a few days • Most blood cells do not divide

7. Erythrocytes (RBCs) Figure 18.3

8. Erythrocyte Function Figure 18.4a, b

18. Hematopoiesis • Blood cell formation • Hematopoiesisoccurs in the red bone marrow

19. Production of Erythrocytes: Erythropoiesis Figure 18.5

20. Hormonal Control of Erythropoiesis Figure 18.6

21. Heart Anatomy

22. Figure 19.4e

23. Heart Covering & Heart Wall • Pericardium • Epicardium • Myocardium • Endocardium Figure 19.2

24. Figure 19.4e

25. Atria Figure 19.4e

26. Ventricles Figure 19.4e

27. Major Vessels Figure 19.4e

28. Pathway of Blood through the Heart and Lungs • Right atrium  tricuspid valve  right ventricle  pulmonary semilunar valve  pulmonary arteries lungs  pulmonary veins  left atrium bicuspid valve  left ventricle aortic semilunar valve aorta systemic circulation

29. Pathway of Blood through the Heart and Lungs Figure 19.5

30. Coronary Circulation • Functional blood supply to the heart • Shortest circulation • Arterial supply arises from the base of the aorta • Right coronary artery • Left coronary artery

31. Homeostatic Imbalances • Angina pectoris • Myocardial infarction

32. Heart Valves • Heart valves insure unidirectional blood flow through the heart • Atrioventricular(AV) valves • Bicuspid • Tricuspid

33. Heart Valves Figure 19.9

34. Heart Valves • Aortic semilunar valve • Pulmonary semilunar valve • Semilunar valves prevent backflow of blood into the ventricles

35. Heart Valves Figure 19.10

36. Thought Question

38. Microscopic Heart Muscle Anatomy Figure 19.11b

39. Skeletal vs. Cardiac Muscle • Means of Stimulation • Cardiac muscle cells are self-excitable and can initiate their own depolarization

40. Heart Physiology: Intrinsic Conduction System

41. Figure 12.10

42. Figure 12.22

43. Figure 12.23

44. Skeletal vs. Cardiac Muscle • Means of Stimulation • Cardiac muscle cells are self-excitable and can initiate their own depolarization • Organ versus Motor Unit Contraction • Heart contracts as a unit or not at all

45. Skeletal vs. Cardiac Muscle • Means of Stimulation • Cardiac muscle cells are self-excitable and can initiate their own depolarization • Organ versus Motor Unit Contraction • Heart contracts as a unit or not at all • Length of Absolute Refractory Period • Long refractory period • Sodium channels are inactivated for almost as long as the contraction

47. Energy Requirements • Needs oxygen to produce ATP • Can use multiple fuel molecules including glucose and fatty acids

48. Homeostatic Imbalances • If heart does not get enough oxygen  production of lactic acid • Gap junctions close and cells become electrically isolated • If area is large, then pumping activity of the heart can be impaired

49. Heart Physiology: Sequence of Excitation Figure 19.14a

50. Thought Questions