This document discusses age-related physiological changes and functional decline in multiple body systems. It outlines that overall body system function declines with age and that specific organs like the cardiovascular, pulmonary, central nervous, renal, liver, immune, gastrointestinal, and endocrine systems are most affected. For each system, it describes both anatomical changes like decreased kidney size and functional changes like lower maximal oxygen consumption that occur with aging and can impact health and disease presentation in older adults.

1. Balamurugan Tangiisuran, PhD Discipline of Clinical Pharmacy School of Pharmaceutical Sciences Universiti Sains Malaysia b.tangiisuran@gmail.com

2. Age-related Physiological Changes and Functional Decline
•Types of Changes Expected with Age:
–Overall decline in body system function
–Variable decline in specific organs and systems
–Different presentations of diseases and symptoms

3. Age-related Physiological Changes and Functional Decline
•Factors contributing to variations in Functional Decline
–Aging process
–Disease
–Adverse environmental factors
–Adverse lifestyles

4. Age-related Physiological Changes and Functional Decline
•System and organs most affected by aging
–CV system
–Pulmonary system
–CNS and brain
–Renal system and kidneys
–Liver
–Immune system
–GI system
–Endocrine system

5. Effects of aging on the CV SYSTEM
•Overall system function – generally sufficient for needs of aging adults
•Heart
–Size of heart stays the same
–Heart wall thickens with age
–Diastolic filling rate decreases, with atrial contribution to ventricular filling normal
–Systolic BP at rest increases, with end systolic volume and ejection fraction not significantly altered

6. Effects of aging on the CV SYSTEM
•Peripheral circulation
–Maximal oxygen consumption decreases
–Beta-adrenergic modulation decreases, alpha-adrenergic response normal
–Stroke volume increases, counteracting decreased heart rate

7. Effects of aging on the Pulmonary System
•Trachea and Central Airways increase in size, leading to:
–More anatomic dead space
–Decreased lung weight
•Chest wall thickens, leading to:
–Loss of elastic recoil in the lung
–Increased closing volume
–Decreased maximum expiratory flow
–Increased risk for respiratory failure

8. Effects of aging on the Central Nervous System and Brain
•Brain mass and cerebral blood flow decreases, leading to:
–Decreased coordination
–Prolonged reaction time
–Impairment of short-term memory
–Decreased sensory conduction time
–More permeable BBB

9. Effects of aging on the Central Nervous System and Brain
•Serotonin system changes affect neuronal functions such as:
–Pain
–Feeding
–Sleep
–Sexual behavior
–Cardiac regulation
–Cognition

10. Effects of aging on the Kidneys and Renal SystemKidneys System
•Anatomic changes:
–Kidney size decreases
–Number of glomeruli decreases
–Renal tubules changes
–Renal vasculature changes

11. Effects of aging on the Kidneys and Renal SystemKidneys System
•Functional changes
–Mean ClCr rate decreases
–Renal blood flow declines
–Conservation of sodium is reduced due to:
•Lower plasma renin activity
•Urinary aldosterone excretion

12. Effects of aging on the Liver
•Overall function less affected by age than other organs
•Liver size decreases
•Hepatic blood flow decreases, leading to altered metabolic clearance of certain drugs

13. Effects of aging on the Immune System
•Cell-mediated responses decrease
•Humoral responses decrease
•Thymus size decreases
•T-cell function is altered
•B-cells produce less antibodies

14. Effects of aging on the Gastrointestinal System
•Oral cavity:
–Traumatic oral lesions
–Xerostomia

15. Effects of aging on the Gastrointestinal System
•Stomach
–Gastric muscular atrophies
–Gastric mucosa thins
–Submucosa is infiltrated with elastic fibers
–Gastric secretion decreases
–pH increases
•once thought to be a consequences of aging, is now thought related to latent H.pylori infections which result in gastric mucosal atrophy and loss of acid producing parietal cells
–Gastric emptying slows

16. Effects of aging on the Gastrointestinal System
•Small Intestine and Colon
–Nutrition absorption decreases (e.g., vitamn D, calcium)
–Motility remains intact
–Constipation and fecal incontinence is common

17. Effects of aging on the Endocrine system
•Regulatory and feedback mechanism deteriorate
•Binding affinities and receptors decrease
•Glucose tolerance decreases
•Production of sex hormones decreases

18. Dr. BalamuruganBalamurugan TangiisuranTangiisuran | School of Pharmaceutical SciencesSciences b.tangiisuran@gmail.com @DrTangiisuran http://geriatricpharmacy.wordpress.com/