Chapter 4
 Circulatory System - Notes  (Changes and Suggestions in blue and green - 3/6/06)
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 1. Name and explain the importance of the four ways the circulatory system helps maintain homeostasis.

     1. transportation to supply nutrients and remove wastes (and secretions)
     2. defense against microbes and foreign or harmful chemicals
     3. temperature control to keep reactions going fast enough without causing damage to molecules from over heating
     4. acid/base balance through the use of buffers to maintain molecular structure and function

 2. Briefly describe the importance of adaptability in the circulatory system's roles in transportation, defense, and temperature control.

     - adaptability provides adjustments when body activities increase or decrease and body needs increase or decrease

 3. Describe the functioning and the importance of heart valves.

     - heart valves prevent blood from moving backward, which reduces circulatory efficiency and overworks the heart

 4. Briefly describe the overall effects from age changes in the cardiac cycle, heart valves, endocardium, and epicardium, and cardiac vessels.

     - age changes in these features have no significant effect on heart functioning

 5. Describe the effects of aging on cardiac output and on the heart's efficiency at rest and during exercise.

     - cardiac output remains unchanged at rest and during exercise though the heart's efficiency decreases (O2 utilization increases) with age

 6. Describe two ways by which compensatory age changes result in no age change in cardiac output (at rest or during exercise).

     1. increases in norepinephrine compensate for decreased coronary sensitivity to norepinephrine
     2. slight dilation and hypertrophy of the left atrium compensate for left ventricular stiffness and tendency for slower filling
     3. slight dilation and hypertrophy of the left ventricle compensate for high blood pressure (higher afterload)

 7. Describe the characteristics of exercise programs that improve cardiac functioning in older people.

     - programs must have vigorous, extended, and frequent exercise

 8. Describe the trends in heart disease (incidence, severity) as age increases and describe the reasons for these trends.

     - incidence and severity increase with age due to (1) increased chances and duration of exposure to risk factors, (2) provision of adequate time for development of significant disease, (3) decrease cardiac efficiency -> incr. O2 use

 9. Rank heart disease among the elderly with regard to incidence and causes of death.

     - ranks 6th to 4th among chronic diseases, is the leading cause for getting medical attention after age 64, and is the leading cause of death

10. Explain why adequate coronary blood flow is necessary.

     - supplies O2 to heart muscle to supply energy

11. Describe the ways that coronary atherosclerosis leads to inadequate coronary blood flow and describe the effects resulting from inadequate coronary blood flow.

     - atherosclerosis cause (1) narrowing, (2) roughening, and (3) stiffening of vessels
     - inadequate blood flow causes cell injury, weaker beats, decreased circulation, and if severe enough, causes cell death (M. I.), and severe decreases in circulation
        See photos of normal arteries, atherosclerosis, and heart disease under Chapter 4 – Circulatory System at microscopic views at .

12. Explain what happens during angina and during a heart attack (myocardial infarction, M. I.)

     - angina = pain from cell injury (reversible)
     - heart attack = cell death (irreversible)

13. Explain why following preventative measures for coronary atherosclerosis and the resulting coronary disease is important in biological as well as other ways in a person s life.

     - prevent (1) threat to health and life, (2) disruption of life of victim and others, (3) disability, (4) social, psychological and economic impacts for victim and others
     - reduce risk of death

14. Name the three most important risk factors for coronary atherosclerosis and describe ways by which these risk factors can be reduced or eliminated.

     1. high blood pressure
     2. smoking
     3. high blood lipoproteins (cholesterol and LDLs)

15. Name seven risk factors for coronary atherosclerosis.

     - smoking, high blood pressure, high blood lipoproteins, diabetes mellitus, family history, increasing age, high blood homocysteine levels, low exercise, obesity, stress, menopause, being male, type A personality, high blood iron levels, periodontal disease

16. Explain the interrelatedness among risk factors for coronary atherosclerosis.

     - geometric synergism

17. Explain how congestive heart failure develops and describe how it causes problems.

     - overworked heart gets too wide and too thick causing weakness and decreased circulation including pulmonary congestion, edema, and varicose veins

18. Describe the main harmful effect from valvular heart disease.

     - valvular disease overworks the heart causing CHF

19. Describe the overall effects from age changes in each of the three layers in large arteries andin smaller arteries.

     - intima: aging -> no significant effect
     - media in large arteries: aging -> thickening, stiffening, limited widening, and limited lengthening -> initial compensation followed by incr. systolic BP -> incr. cardiac workload and incr. risk of atherosclerosis
     - media of smaller arteries: aging -> decr. sensitivity to neurons -> (1) decr. dilation with ischemia -> decr. maximum rate of work plus (2) decr. adaptability for temperature control
     - externa: aging -> no significant effect

20. Explain how age changes in arteries lead to increased systolic blood pressure.

     - reduced elasticity -> decr. ability to compensate for systolic cardiac output -> incr. systolic BP

21. Describe two significant effects from high blood pressure.

     - incr. systolic BP -> (1) incr. cardiac workload and (2) incr. risk of atherosclerosis

22. Name two areas of the body where aging causes a decrease in the number of arteries.

     - (1) skin, (2) kidneys

23. Name and describe the effects from the four changes in arterial properties caused by atherosclerosis.

     - narrowness -> decr. flow = decr. service for cells
     - roughness -> clot formation -> decr. flow -> decr. service for cells
     - stiffness -> decr. ability to dilate -> decr. adaptability with incr. demand by cells
     - weakness -> aneurysms -> (1) pressure on structures, (2) clot formation, (3) bleeding

24. Perform objectives 8, 10, 11, 13-16 for atherosclerosis in any body area. (These are the same for the corresponding heart objectives except for the addition of weakness and aneurysms.)

     - incr. incidence and severity (exposure to risks plus time to develop)
     - need adequate flow to service cells
     - (see objective 23)
     - (see objectives 13-16)

25. List and describe mechanisms believed to promote or cause the development of atheromas.

     - free radicals from chemicals that signal blood vessels (nitric oxide)
     - free radicals from lipids (lipid peroxides)
     - accumulation of lipids in vessel wall cells (foam cell formation)
     - destruction of elastin fibers in artery walls by elastase
     - glycation of arterial wall proteins
     - immune responses against arterial wall proteins
     - hormonal imbalances allowing or promoting free radical damage in vessel walls

26. Describe two age changes in capillaries and explain the effects from these changes.

     1. incr. irregularities -> decr. flow -> decr. service for cells
     2. incr. thickness of basement membrane -> decr. exchange for cells
     3. decr. # of pores -> decr. exchange for cells

27. Describe the overall effects from age changes in veins.

     - no effects

28. Describe varicose veins, indicate that they are a disease, explain how they develop, name and describe three effects they produce, and name and describe three ways to reduce their occurrence.

     - expanded veins
     - do not develop in all people
     - cause by chronic passive congestion
     - cause cosmetic effects, pain, infection, edema, ischemia, bleeding (G.I. tract), pulmonary embolism
     - avoid long standing, constrictive posture or clothing, inactivity, chronic cough, alcoholism: wear support hosiery, get exercise

29. Describe what hemorrhoids are and name three ways to reduce their occurrence.

     - varicose veins at the anus
     - avoid constipation, forced bowel movements, chronic cough, alcoholism: get adequate fiber, water, exercise, accessible toilet facilities

30. Describe the overall effects of age changes in the lymphatic system (except for lymphocytes).

     - no significant changes

31. Describe the overall effects from age changes in blood plasma, red blood cells, platelets, and white blood cells.

     - plasma -> no change
     - RBCs -> no change
     - platelets -> slight incr. clotting -> incr. risk of thrombus
     - WBCs (except lymphocytes) -> possibly  decr. defense (possibly decr. in storage, mobilization, mobility, chemotaxis, phagocytosis)

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