The physiological and psychological impact of aging can be seen across multiple body systems. The cardiovascular system shows a thickening of arteries and decreased elasticity, along with a lower cardiac output and increased risk of atherosclerosis. The respiratory system exhibits narrowed bronchioles, decreased lung capacity and weaker respiratory muscles. The musculoskeletal system demonstrates loss of bone and muscle mass, and increased risk of osteoporosis and osteoarthritis. Finally, the nervous system sees a loss of brain volume and neurotransmitters, slower reflexes, and increased risk of dementia and Alzheimer's disease.

1. The Physiological & Psychological Impact of Ageing Part I Systemic Impact

2. Structure of Lecture 1. Cardiovascular system 2. Respiratory System 3. Musculo-skeletal system 4. Nervous system

3. 1. Cardiovascular system

4. 1. Cardiovascular system Main functions in homeostasis: • Transportation of materials around the body - useful products to cells - harmful by-products away • Defence mechanisms - removal of dangerous chemicals • Temperature control - dermal blood vessels • Acid/Base Balance - optimal pH 7.35-7.45

5. The Heart

6. Deposits of collagen and fatty tissue into heart muscle. Walls of arterioles = thicker with less elasticity. Longer time between diastole and systole of heart muscles. Decreased cardiac output (1/3 less Oxygen from 20-80 years). More difficult to do strenuous exercise. Ageing changes of the Heart

7. Cardiac Output (CO) = Stoke Volume (SV) x Heart Rate (HR) The Cardiac Cycle Cardiac Cycle

8. Blood Pressure Changes Associated with Ageing • 40% of the elderly have systolic pressure above the safe maximum (160 mmHg) • Systolic Blood Pressure -  5-8 mmHg per decade after 40-50 yrs - in females systolic BP stops rising after 70 yrs • Diastolic Blood Pressure -  1 mmHg per decade

9. Pulmonary Congestion • Induced by blood remaining in the left ventricle after contraction. • Inhibits blood flow from the lungs & raises blood pressure in the lung capillaries which forces fluid out of the capillary walls • This PULMONARY OEDEMA reduces respiratory function and causes individuals to feel out of breath more quickly.

10. Coronary Artery Disease • The older heart requires more oxygen to pump the same amount of blood around the body as a young heart. • This is not important as long as the coronary arteries remain normal. • However, age changes cause deficiencies in the normal functioning of coronary arteries. • ATHEROSCLEROSIS prevents adequate blood supply to the heart. • This causes MYOCARDIAL INFARCTION

11. Coronary Arteries

12. Age Changes in Arteries • Loss of elasticity - accumulation of calcium & lipids - breakage of elastic fibres This loss of elasticity means that vessels are less able to be stretched by blood flow. -  systolic blood pressure

13. • Widening & Lengthening At first this compensates for elasticity loss but fibres are eventually stretched until they stretch no more. Each heart contraction causes a rapid and dramatic rise in systolic BP This leads to increases in cardiac O 2 demand • Diminished Elastic Recoil Causes slowing of blood flow through arteries

14. ATHEROSCLEROSIS • Most common form of arterial disease forming one of a group of arterial diseases known as ARTERIOSCLEROSIS. • Causes the formation and enlargement of scar like material called PLAQUE in the walls of arteries. • Plaque cases arteries to narrow and thus reduces blood flow. • It also causes stiffening of the arteries reducing their ability to dilate when oxygen demands in crease.

15. Age Changes in Arteries

16. • Atherosclerosis also involves roughening of the inner lining of arteries and exposure of underlying collagen. • Both of these factors promote the formation of clots which can impede and totally block blood flow. • Atherosclerosis causes: - heart attacks - strokes - aneurysms - kidney disease - muscle problems in the legs

17. Mechanisms Promoting Atherosclerosis • Endothelial Dysfunction • Free Radicals - formation of lipid peroxides • Blood Low Density Lipoproteins (LDLs) - eg cholesterol & triglycerides • Elastase - an enzyme that breaks down elastic fibres • Glycation - the use of glucose to form cross links between protein molecules - produces age-related glycation end products (AGEs) and FRs

18. Risk Factors in Atherosclerosis Smoking Blood pressure High blood LDLs Diabetes Mellitus Family history Advancing age

19. Age Changes in Capillaries • Become narrower and irregular in shape • Decrease in number • Walls become thicker • Decreased permeability • Reduce the ability of the circulatory system to adjust quickly to changes in the demands of the body

20. Age Changes in Veins • Thickening of the walls and valves • Varicose veins -  vein diameter - promotes clot formation thrombus  embolus

21. 2. The Respiratory System Main functions for homeostasis: • Gaseous exchange - obtaining 0 2 & eliminating CO 2 Ventilation (breathing) Perfusion (pulmonary circulation) Diffusion (0 2 in & CO 2 out)

22. Age Changes Affecting Ventilation • Narrowing of Bronchioles • Decreased alveolar surface area • Respiratory muscles become weaker • Decrease in lung elasticity Consequences: Rate at which air can circulate through the system Ventilation is made more difficult and this  0 2 supply and  CO 2 in the blood.

23. Ventilation Minute Volume = Vol. Per breath x breaths per minute Vital Capacity = Tidal Volume + Inspiratory Reserve Vol + Expiratory Reserve Vol. VC = TV + IRV + ERV Total Lung Capacity = TV + IRV + ERV + Residual Vol. (TLC) (RV) 6.0 litres 2.7 2.2 1.2 0

24. • Ageing does not affect the TLC but does affect the volumes of air that can be moved. • The loss in elasticity of the lungs leads to  IRV & ERV • Tidal volume increases and there are increases in residual volume • The vital capacity of the lungs decreases • These volume changes have two effects: 1) decrease in maximum minute volume. 2)  VC with  RV means less fresh air is inspired. This  rate of diffusion.

25. Diseases of the Respiratory System • Respiratory diseases (excluding lung cancer) are the fourth leading cause of death in the elderly. • Lung cancer • Chronic Bronchitis - inflammation of the bronchioles -  mucous production  ventilation by making airways narrower • Emphysema - destruction of parts of the the lungs e.g. bronchioles & alveoli • Pneumonia - inflammation of the lungs  infection

26. 3. Musculo-Skeletal System Main functions in homeostasis: - movement - support - heat production - protection - mineral storage - blood cell production

27. Age changes in muscles •  nerve-muscle interactions •  muscle mass •  blood flow in muscles Consequences •  Reaction Times (RTs) •  speed of movement •  endurance

28. Skeletal Age Changes • Loss of bone matrix (more extensive in post menopausal females) OSTEOPOROSIS • Stiffening of hyaline Cartilage between joints due to loss of H 2 O and Ca 2+ deposition. OSTEOARTHRITIS Consequences • Generalised weakening of the bone (falls tend to cause more fractures in elderly) •  joint mobility

29. 4. Nervous System Main functions for homeostasis: • monitoring • communication • stimulation • memory • information processing

30. Age Changes in the Nervous System • Loss of brain volume •  neurotransmitters, slower nerve conduction rate. •  numbers & changes in the structure of synapses •  numbers of motor neurons • slower reflexes

31. • memory loss -  short term memory (STM) - greatest decline in STM is for information presented verbally and quickly. - long term memory is largely unaffected • increase reaction time (  accidents?) • vocabulary & conversation • sleep pattern changes. • personality changes?

32. Diseases of the Nervous System Cerebro-Vascular Accidents (CVAs) or Strokes • third leading cause of death in the over 65 age group • occur when blood supply to the brain is disrupted - common result of atherosclerosis - hypertensive haemorrhagic stokes • Effects depend upon the site of blockage/leakage in the brain: - paralysis/paresis - loss of language skills - visual field defects

33. Dementias A broad category of diseases which involve a serious decline in memory and a decline in at least one other major function. - sufferers cannot carry out normal activities - difficulties must be experienced on a long term basis - caused by an identifiable physical abnormality • Number and rate of dementia cases are  • Incidence rate rises exponentially with age • Effects:  STM, loss of motor function, personality changes

34. Alzheimer’s Disease (AD) • Fifth leading cause of death in the US • AD is becoming a more important factor of ageing as risks of heart disease & cancer decline • Early onset or familial AD Late onset or senile dementia of the Alzheimer type • Causes: Genetic abnormalities? Normal part of the ageing process ? • Changes in the brain: senile plaques  beta amyloid neurofibrillar tangles  dead neurons low levels of acetylcholine