Cardiovascular System

1. Cardiovascular System

2. Cardiovascular System Components • Circulatory system • Pulmonary system • Purposes: • Transport O2 to tissues and remove waste • Transport nutrients to tissues • Regulation of body temperature

3. Circulatory System • Heart • Pumps blood • Arteries and arterioles • Carry blood away from heart • Capillaries • Exchange nutrients with tissues • Veins and venules • Carry blood toward heart

7. Systole Contractile phase of heart Electrical and mechanical changes Diastole Relaxation phase of heart Takes twice as long as systole Cardiac Cycle

8. Arterial Blood Pressure • Expressed as systolic/diastolic • Normal – 120/80 mmHg • High – 140/90 mmHg • Systolic pressure (top number) • Pressure generated during ventricular contraction • Diastolic pressure • Pressure during cardiac relaxation

11. Electrical Activity of the Heart • Contraction of heart depends on electrical stimulation of myocardium • Impulse is initiated on right atrium and spreads throughout the heart • May be recorded on an ECG

12. Heart Rate • Range of normal at rest is 50 – 100 b.m • Increases in proportion to exercise intensity • Max. HR is 220 – age • Medications or upper body exercise may change normal response

13. Sympathetic control Stimulates “fight or flight” response Speeds up heart rate and stroke volume Sympathetic tone > 100 bpm Parasympathetic control Connected to vagus nerves Slows down heart rate Parasympathetic tone 60 – 100 bpm Autonomic Nervous System Control of Heart Rate

15. Components of Blood • Plasma • Liquid portion of blood • Contains ions, proteins, hormones • Cells • Red blood cells • Contain hemoglobin to carry oxygen • White blood cells • Platelets • Important in blood clotting • Hematocrit • Percent of blood composed of cells

16. Changes in Cardiac Output • Cardiac output increases due to: • Increase in heart rate • Linear increase to max • Max HR = 220 - age • Increased stroke volume • Plateau at ~40% of VO2 max • Oxygen uptake by the muscle also increases • Higher arteriovenous difference

17. Causes of High Blood Pressure • Age • Race • Heredity • Diet • Stress • Inactivity

18. How to have a heart attack Everyone’s doing it, so it must be the “in” thing to do

19. Be Old • Relative risk of CHD increases with age

20. Have a family history of CHD • The more blood relatives one has with CHD, and the younger they are (were), the higher the relative risk

21. Be a Man • Males have 5-6 times the relative risk of CHD of females • Why? Estrogen may be protective

22. Unalterable Risk Factors for CHD • Age • Family History • Sex

23. Alterable Risk Factors • Things you can do something about…

24. Be fat • Obesity increases CHD risk • How much fat is too much? • Males - > 25% • Females > 30%

25. Eat a high fat diet • High fat foods increase plaque within arteries and contribute to atherosclerosis

26. Have High Cholesterol • Total cholesterol/HGH ratio above: • Males – 4.5/1 • Females – 4/1 • Increases relative risk of CHD

27. Have High Blood Pressure • High blood pressure forces the heart to work harder • How high is too high? • > 140/90

28. Smoke • Smokers are more likely to die of heart attack than cancer • Smoking is the single most important alterable risk factor

29. Be a Type A personality • Type A personalities are: • High-strung • Achievement-oriented • Aggressive • Time-conscious

30. Live a stressful lifestyle • No one, lying on their deathbed, has said they wished they had spent more time at the office.

31. Have Other Diseases • Diabetes • Ulcers • Obesity

32. Don’t Exercise • If you get the urge to exercise, lie down until the feeling passes.

33. Heart Disease and Stroke Statistics — 2010 Update

34. CVD disease mortality trends for males and females(United States: 1979-2006). Source: NCHS and NHLBI.

35. Age-adjusted death rates for CHD, stroke, lung and breast for white and black females(United States: 2006).Source: NCHS.

36. Deaths from cardiovascular disease(United States: 1900–2006). Source: NCHS and NHLBI.

37. Percentage breakdown of deaths from cardiovascular diseases (United States: 2006)* - Not a true underlying cause.Source: NCHS.

38. Prevalence of CVD in adults age 20 and older by age and sex(NHANES 2003-2006). Source: NCHS and NHLBI. These data include coronary heart disease, heart failure, stroke and hypertension.

39. Trends in Heart Transplants (UNOS: 1975-2008). Source: United Network for Organ Sharing (UNOS), scientific registry data.

40. Trends in Cardiovascular Operations and Procedures (United States: 1979-2006).Source: NCHS and NHLBI. Note: In-hospital procedures only.

41. Number of Surgical Procedures in the 10 Leading Diagnostic Groups (United States: 2006).Source: NHDS/NCHS and NHLBI.

42. Cardiovascular 390-459 324.1 225.2 Digestive System 520-579 Mental 290-319 177.7 175.4 Nervous System 320-389 Injury and Poisoning 800-999 172.9 159.1 Respiratory System 460-519 Musculoskeletal system 710-739 126.1 102.7 Neoplasms 140-239 Genitourinary System 580-629 93.8 87.4 Endocrine System 240-279 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 Direct Costs of the 10 Leading Diagnostic Groups (Billions of dollars) (United States: 2010).Source: NHLBI.

43. About cholesterol • Soft, fat-like, waxy substance • Bloodstream and cells • Needed for cell membranes and hormones and to make vitamin D • Comes from 2 sources • Body produces it (mostly genetic) in liver (1000 mg day) • Food sources (animal products – meats, poultry, fish, eggs, butter, whole milk, and cheese, not from plant sources) (100 – 500 mg day) • Foods with trans fats or saturated fats may cause the body to produce more cholesterol

44. About cholesterol • Must be transported through blood • Carriers are called lipoproteins • Low-density lipoprotein (LDL) • High-density lipoprotein (HDL) • Lipoprotein = protein + fat • LDL, more fat, less protein • HDL, more protein, less fat

45. LDL vs. HDL LDL = “bad” Too much can clog arteries by forming plaque Atherosclerosis can cause heart attack or stroke

46. LDL vs. HDL HDL = “good” Tends to carry cholesterol away from arteries and back to liver May also remove excess cholesterol from plaque in arteries, slows buildup

47. Triglycerides Form of fat Also made in body (body fat stored as triglyceride) and from food Help transport dietary fat, metabolism Trigger liver to make more cholesterol, rising LDL and total cholesterol

48. Healthy Levels Source: National Cholesterol Education Program, National Heart, Lung, and Blood Institute • Total cholesterol • Optimal – under 200 mg/dL • Borderline high risk – 200-239 mg/dL • High risk – 240 mg/dL and up • LDL • Optimal – less than 100 mg/dL • Near/Above optimal – 100-129 mg/dL • Borderline high – 130- 159 mg/dL • High – 160 – 189 mg/dL • Very high – 190 mg/dL

49. Healthy Levels • HDL • Low - less than 40 mg/dL • High – above 60 mg/dL (may lower risk for heart disease) • Women tend to have higher HDL due to estrogen (needs to be over 50 mg/dL) • Triglycerides • Normal – less than 150 mg/dL • Borderline high – 150 – 199 mg/dL • High – above 200 mg/dL

50. Common misconceptions Using margarine instead of butter will help lower my cholesterol Thin people don’t have to worry about high cholesterol If a label lists no cholesterol, it’s a “heart-healthy” choice Eggs – good or bad? Women don’t need to worry about cholesterol Only middle-aged people should have their cholesterol checked