Chapter 9: Circulation: The Cardiovascular and Lymphatic Systems

1. Chapter 9: Circulation: The Cardiovascular and Lymphatic Systems

2. Chapter Objectives • The paths of blood flow and electrical conduction through the heart. • Components of an electrocardiogram. • Arteries, arterioles, capillaries, veins, and venules. • Blood pressure and how it is is measured. • Roots pertaining to the cardiovascular and lymphatic systems. • Main disorders that affect the cardiovascular and lymphatic systems. • Medical terms pertaining to the cardiovascular and lymphatic systems. • Functions and components of the lymphatic system. • Medical abbreviations referring to circulation.

3. Key TermsCardiovascular SystemNormal Structure and Function

4. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

5. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

6. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

7. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

8. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

9. Key TermsCardiovascular SystemNormal Structure and Function (cont’d)

10. Key TermsCardiovascular Disorders

11. Key TermsCardiovascular Disorders (cont’d)

12. Key TermsCardiovascular Disorders (cont’d)

13. Key TermsCardiovascular Disorders (cont’d)

14. Key TermsCardiovascular Disorders (cont’d)

15. Key TermsCardiovascular Disorders (cont’d)

16. Key TermsCardiovascular Disorders (cont’d)

17. Key TermsCardiovascular Disorders (cont’d)

18. Key TermsDiagnosis and Treatment

19. Key TermsDiagnosis and Treatment (cont’d)

20. Key TermsDiagnosis and Treatment (cont’d)

21. Key TermsDiagnosis and Treatment (cont’d)

22. Cardiovascular System • Consists of heart and blood vessels • Encompasses blood circulation • Delivers oxygen and nutrients to cells • Carries away waste products

23. Cardiovascular System

24. The Heart • Located between lungs • Endocardium = inside lining; lines chambers and valves • Myocardium = thick muscle layer that makes up heart wall • Epicardium = outside thin lining; covers heart • Pericardium = surrounding fibrous sac • Atria = upper receiving chambers (singular: atrium)

25. The Heart (cont’d) • Ventricles = Lower pumping chambers (singular: ventricle) • Pulmonary circuit (right side to lungs) • Systemic circuit (left side to rest of body) • Chambers separated by septum (walls) • Pumps blood through two circuits • Pulmonary = right side; blood to be oxygenated • Systemic = left side; oxygenated blood to body

26. Roots for the Heart

27. Roots for the Blood Vessels

28. Illustrated Heart

29. Blood Flow Through the Heart • Right atrium receives blood from body • Enters right ventricle and is pumped to lungs • Oxygenated blood returns to left atrium • Enters left ventricle and is pumped to rest of body • One-way valves force blood flow forward • Heart sounds produced when valves close

30. The Heartbeat • Systole = contraction • Diastole = relaxation • Heart beats start with both atria contracting • Heart rate = number of times heart contracts per minute • Pulse = wave of increased pressure

31. The Heartbeat (cont’d) • Ventricles contract • Contractions are stimulated by electrical impulse • Sinoatrial node • Atrioventricular node • AV bundle • Bundle branches • Purkinje fibers

32. Conduction System of the Heart

33. Electrocardiography • Measures electrical activity • Sinus rhythm = one complete cycle • P wave • QRS • T wave • U wave

34. The Vascular System • Arteries and arterioles • Carry blood away from heart • Capillaries • Smallest vessels • Where exchange between blood and tissues happens • Veins and venules • Carry blood back to heart

35. Blood Pressure • Force of blood exerted against wall of blood vessel • Influenced by cardiac output, vessel diameters, total blood volume • Measured by sphygmomanometer • Measured as both systolic and diastolic

36. Principal Arteries

37. Principal Veins

38. Clinical Aspects of the Circulatory System • Atherosclerosis • Accumulation of fatty deposits within artery • Risk factors: • High levels of lipoproteins (especially LDL’s) • Smoking • High blood pressure • Poor diet • Inactivity • Stress • Family history

39. Thrombosis and Embolism • Definitions: • Thrombosis = formation of blood clot • Thrombus = blood clot resulting in tissue death • Embolism = blockage of blood vessel • Embolus = blockage mass • Blockage is usually blood clot • Blockage can also be air, fat, bacteria, or other solid materials • Stroke = blockage in a cerebral vessel

40. Aneurysm • Weakened arterial wall ballooning out • Caused by: • Atherosclerosis • Malformation • Injury • Dissecting aneurysm sometimes ruptures vessel; possible to fix with graft

41. Hypertension • Commonly known as high blood pressure • Contributing factor in many conditions • Defined as systolic > 140, diastolic > 90 • Causes left ventricle to enlarge • First defense: diet and life habits

42. Heart Diseases • Coronary artery disease • Results from atherosclerosis • Early sign is angina pectoris (chest pain) • Diagnosed by: • ECG • Stress tests • Coronary angiography • Echocardiography

43. Heart Diseases (cont’d) • Coronary artery disease (cont’d) • Treatments: • Control of exercise, administration of nitroglycerin • Angioplasty (PTCA) • Bypass (CABG)

44. Heart Diseases (cont’d) • Myocardial infarction (MI) = heart attack • Symptoms: • Precordial or epigastric pain • Pain extending to jaw, arms • Pallor (turns pale) • Diaphoresis • Nausea • Dyspnea (difficulty breathing) • May also be burning sensation similar to heartburn

45. Heart Diseases (cont’d) • MI (cont’d) • Diagnosed by: • Electrocardiography (ECG) • Assays for specific substances in the blood (creatine kinase MB, increased troponin)

46. Heart Diseases (cont’d) • Arrhythmia • Irregularity of heart rhythm • Bradycardia = slower than average • Tachycardia = faster than average • Fibrillation = extremely rapid, ineffective • Regulated/treated: • Artificial pacemaker • Cardioversion with drugs or electric current (defibrillation) • CPR • Ablation

47. Heart Diseases • Heart failure • Heart fails to empty effectively, leading to edema • Treated with rest, drugs, diuretics, diet • Congenital heart disease • Birth defects • Septal • Patent ductus arteriosus • Murmur • Coarctation of the aorta • Most can be corrected surgically

48. Heart Diseases (cont’d) • Rheumatic heart disease • Streptococcus infection damaging heart valves • Treated with antibiotics • May require surgical correction or valve replacement

49. Disorders of the Veins • Varicose veins • Breakdown in valves with chronic dilatation • Contributing factors: • Heredity • Obesity • Prolonged standing • Pregnancy • Treated: • Elastic stockings • Removal

50. Disorders of the Veins (cont’d) • Phlebitis = inflammation of veins • Causes: • Infection • Injury • Poor circulation • Valve damage • Can result in thrombophlebitis (blood clot) • Most damaging if occurring deep