Anatomy of the Cardiovascular System

1. Anatomy of the Cardiovascular System

2. Cardiovascular System • Also circulatory system • Consists of: the heart, arteries, veins, capillaries

3. Heart • Four chamber muscular organ • Comparable to the size of a closed fist • Located in the mediastinum

4. Heart

5. Coverings of the Heart • Pericardium – loose fitting sac surrounding the heart • Fibrous pericardium – tough, loose-fitting, inelastic • Serous pericardium • Parietal layer: lines the inside of the fibrous pericardium • Visceral layer: adheres to outside of the heart • Pericardial space: between parietal and visceral layer • Filled with 10-15mL of pericardial fluid • Decreases friction

6. Walls of the Heart • Epicardium – outer layer • Epicardium = serous pericardium • Myocardium – thick, contractile layer composed of cardiac muscle cells • Endocaridium – interior of cardiac wall

7. Walls of the Heart

8. Chambers of the Heart • Atria – two superior chambers • “Receiving chambers” • Blood from veins enters atria • Ventricles – two inferior chambers • “pumping chambers” • Separated by interventricular septum

9. Valves of the Heart • Permit blood flow in one direction during circulation • Atrioventricular valves (AV valves) • Also cuspid valves • Between atria and ventricles • Semilunar (SL valves) • Between ventricles and vessles

10. Chambers & Valves Trace the blood flow through the heart

11. Blood Supply to the Heart • After traveling through the capillaries of the heart, blood empties into the Right atrium via the vena cavas

12. Conduction System of the Heart • Sinoatrial Node (SA Node) • Pacemaker of the heart • 100s of cells in the R atrium near the opening of the superior vena cava • Atrioventricular Node (AV Node) • Left lower border of R atrium

13. Types of Blood Vessels • Artery – carries oxygenated blood away from the heart • Arteriole: small artery • Precapillary sphincters: regulate the blood flow into capillaries

14. Types of Blood Vessels • Vein – carries unoxygenated blood towards the heart • Venules: small vein

15. Types of Blood Vessels

16. Types of Blood Vessels • Capillaries – arterial system switches to venous system • “primary exchange vessels” • Transport materials to and from the cells • Speed of blood flow decreases to increase contact time

17. Types of Blood Vessels

18. Structure of Blood Vessels • Tunica adventitia - outermost layer • Fibrous connective tissue • Holds vessels open; prevents tearing of vessels walls during body movements • Larger in veins than arteries • Tunica media – middle layer • Smooth muscle and elastic CT • Helps vessels constrict and dilate • Larger in arteries

19. Structure of Blood Vessels • Tunica intima – innermost layer • Composed of endothelium • Semilunar valves present in veins • One cell thick in capillaries

20. Circulatory Routes • Systemic Circulation – blood flow from the L ventricle to the body & back to the R atrium • Pulmonary Circulation – blood flow from the R ventricle to the lungs and back to the L atrium

21. Circulatory Routes

22. Aorta

23. Arch of aorta Subclavian (L and R) Brachiocephalic common carotid (L and R) Axillary (L and R) Brachial (L and R) Radial Ulnar Abdominal aorta Common iliac External iliac Femoral Popliteal Posterior tibial Anterior tibial Dorsal pedis Systemic Arteries

25. Superior vena cava Inferior vena cava External jugular Internal jugular Brachiocephalic (L and R) Subclavian (L and R) Cephalic axillary Basilic Median basilic Median cubital Common iliac External iliac Femoral Popliteal Great saphenous Small saphenous Systemic Veins

27. Pericardium Disorders • Pericarditis – inflammation of the heart • Causes: trauma, viral or bacteria infection, tumor • Edema causes visceral and parietal layers to rub together = chest pain • Pus or blood build up in pericardial space • S/S • Pain with respirations or coughing, dyspnea, restlessness • Complications: Pericardial Effusion, Cardiac Tamponade • Treatment: • Antibiotics, pain meds, antiinflammatory meds, pericardiocentesis (Cardiac Tamponade)

28. Heart Valve Disorders • General Principles: • Congenital defect: decreased pumping efficiency • Incompetent valve leak: allows backflow into previous chamber • Stenosed valves: narrowed valve; slowing blood from out of chamber

29. Heart Valve Disorders • Mitral Valve Prolapse (MVP) • Flaps of mitral valve extend back into L atrium causes leaking • Mostly genetic basis • 1 in 20 people • S/S: most asymptomatic; chest pain, fatigue • Treatment: valvuloplasty

30. Mitral Valve Prolapse

31. Heart Valve Disorders • Aortic Regurgitation • Blood leaks back into L ventricle during ejection into the aorta • Volume overload in L ventricle, hypertrophy, dilation of L ventricle • Complications: myocaridal ischemia • Treatment: valvuloplasty

32. Myocardium Disorders • Atherosclerosis • Type of arteriosclerosis • Lipids build up on the inside of vessel walls  calcify  vessels hard & brittle • Risk factors: cigarette smoking, high fat/cholesterol diet, hypertension

33. Atherosclerosis

34. Myocardium Disorders • Myocardial Infarction • “Heart Attack” • Coronary thrombosis: clot • Coronary embolism: mobilized clot • Occlude coronary artery  heart tissue deprived of oxygen  cell death • S/S: • Angina pectoris – severe chest pain resulting from inadequate oxygen to myocardium • Treatment: Coronary Bypass Surgery • Veins are harvested from other areas of the body and used to bypass obstructions

36. Myocardium Disorders • Congestive Heart Failure (CHF) • “Left-sided Heart Failure” • Inability of the L ventricle to pump blood efficiently • Causes: myocardial infarction • S/S: decreased pumping pressure in systemic circulation; retained fluids • Can lead to congestion in pulmonary circulation  pulmonary edema  right-sided heart failure • Treatment: heart transplant

37. Congestive Heart Failure

38. Myocardium Disorders • Coronary Artery Disease (CAD) • Leading cause of death in US • General term to describe decreased blood flow to myocardium & associated side effects

39. Disorders of the Arteries • Arteriosclerosis • Arteries become occluded, weak and hardened • Complications: ischemia, necrosis, gangrene • Risk factors: age, diabetes, high fat/cholesterol diet, hypertension, smoking • Treatment: vasodilators, angioplasty, stent placement, bypass surgery • Complications: aneurysm

40. Angioplasty

41. Disorders of Veins • Varicose Veins • Enlarged veins caused by pooling • Results in varicosities or varices (“spider veins”) • Risk factors: standing for long periods • Semilunar valves widen  more pooling • Treatment: compression stockings, surgical removal

42. Varicose Veins

43. Disorders of Veins • Phlebitis – vein inflammation • Causes: irritation by IV catheter • Thrombophlebitis • Deep vein thrombosis (DVT) • Phlebitis caused by a clot • S/S • Pain, redness, swelling • Complications • Pulmonary embolism

44. DVT

45. Pulmonary Embolism

46. Venous Stasis Ulcers • Result of chronic vein insufficiency • Lack of oxygen to peripheral tissues • Elevate leg & apply pressure • Irregular edges • “Aching” pain