Effects of Aging on Body Systems

Aging and its Effects on Different Body Systems

• The elderly are individuals aged 65 years and older.
• Aging progresses at varying rates in different individuals and within different body systems.
• Aging leads to a progressive decline and deterioration of functional properties at the cellular, tissue, and organ level, resulting in a loss of homeostasis, decreased adaptability, and increased vulnerability to disease and mortality.

Special Sensations

• Vision acuity and field of vision decrease.
• Smell and taste sensation decrease, making food less appealing, decreasing appetite, and potentially leading to weight loss.
• Hearing sensation decreases.

Nervous System

• Intellectual function and speed of learning decrease.
• Gradual loss of recent memory occurs.
• Sensory changes include decreased sensation, such as hypoesthesia (e.g., vibration).
• Motor changes include decreased muscle power, senile tremors, and decreased or absent reflexes.
• Psychological changes include emotional instability.

Respiratory System

• Elastic tissue of the lungs deteriorates, leading to dilated and thin-walled alveoli.
• The ciliary transport system is impaired, reducing mucous and foreign material clearance.
• Decreased ciliary transport increases risk of hypothermia in cold weather and heat stroke in hot weather.

Body Temperature

• Body temperature in elderly individuals is lower by about 0.2-0.5 degrees Celsius compared to adults due to reduced basal metabolic rate, atrophy of skeletal muscles, and impaired circulation.

Body Shape

• Body composition changes with age.
• Fat deposition shifts towards the center of the body, increasing by up to 30%.
• Lean body mass decreases.
• Bones lose minerals, becoming less dense.
• Total body water reduces, making elderly individuals more susceptible to dehydration.

Immune System

• The number of circulating lymphocytes decreases.
• T cell response weakens, increasing susceptibility to infection and malignancy.
• Increased production of autoantibodies occurs.

Endocrine System

• Hormone secretion decreases.
• Hormone efficacy on target tissues decreases.

Changes in Water and Electrolytes

• Potassium levels decrease in elderly individuals due to reduced lean body mass.
• Total body water decreases due to disruptions in thirst and thermoregulatory mechanisms, emphasizing the importance of encouraging adequate water intake to prevent dehydration.
• Calcium levels decrease due to reduced absorption and decreased vitamin D levels.
• Sodium levels increase with age, leading to increased sensitivity to dietary sodium.

Anti-aging Measures

• Maintain ideal body weight.
• Eat breakfast daily.
• Engage in regular exercise.
• Avoid stress and smoking.
• Obtain 7-8 hours of sleep per day.
• Undergo regular checkups for early disease detection.
• Ensure good nutrition, including adequate water intake, nourishing food rich in minerals, trace elements, and vitamins, and reduced caloric intake to prevent obesity.

Atypical Presentation of Diseases in Elderly Individuals

• Due to age-related physiological changes, interactions between chronic and acute illness, and under-reporting of symptoms, elderly individuals may exhibit atypical signs and symptoms, including the absence of expected symptoms, unusual symptoms, or symptoms opposite to what is usually observed.

Dementia

• A progressive neurodegenerative disease characterized by cognitive decline, memory impairment, and behavioral changes.
• Stages of dementia:
  • Mild stage: Forgetfulness, difficulty with daily activities.
  • Moderate stage: Verbal and physical agitation, wandering, sleep disturbances.
  • Severe stage: Bedridden, incontinence.
• Evaluation:
  • History from family or friends about changes in daily activities or personal behavior.
  • Physical examination to rule out dementia mimics, such as severe anemia, hypothyroidism, or B12 and folate deficiency.
  • Cognitive assessment using the Mini-Mental State Examination (MMSE) with a score of 18-25 suggesting dementia.
  • Laboratory tests: CBC, thyroid profile, B12 and folate levels.
  • Imaging: MRI to show hippocampal atrophy, PET amyloid or PET tau scan.
  • Gold standard: Brain autopsy and biopsy to identify senile plaques and neurofibrillary tangles.
• Treatment:
  • Environment: Cueing and scheduling activities.
  • Family care: Psychosocial supportive therapy is crucial as 50% of caregivers develop depression within 5 years.
  • Non-medical measures: Education, psychosocial support, ongoing care, and follow-up.
  • Medical treatment: Acetylcholine esterase inhibitors (donepezil, rivastigmine) to increase acetylcholine levels for memory, used in mild to moderate stages where sufficient neurons remain for acetylcholine to act. NMDA receptor blocker (memantine). Other treatments include anti-inflammatory drugs and estrogen.
  • Treatment of associated disorders: Anxiety, sleep disorders, delirium.

Delirium

• A geriatric emergency characterized by acute onset, cognitive and attention impairment, and fluctuating course throughout the day.
• Not related to memory.
• The most frequent complication of hospitalization among the elderly.
• Risk factors:
  • Modifiable: Alcoholism, alcohol withdrawal, anemia, pain, comorbid conditions.
  • Non-modifiable: Age over 65 years, Parkinsonism, associated diseases (CKD, CHF, hepatic disease).

Urinary Incontinence

• Involuntary loss of urine.
• Types:
  • Stress incontinence: Leakage during physical activity.
  • Urgency incontinence: Sudden urge to urinate followed by involuntary leakage.
  • Overflow incontinence: Constant dribbling of urine.
• Causes:
  • Weakened pelvic floor muscles, overactive bladder, bladder outlet obstruction, neurological disorders.
• Treatment:
  • Lifestyle and behavioral interventions: First-line treatment, including smoking cessation, caffeine and alcohol reduction, weight loss, and modified fluid intake.
  • Pelvic floor exercises (Kegel exercises): To strengthen pelvic floor muscles.
  • Medical treatment for urge incontinence:
    • Duloxetine (first-line),
    • Antimuscarinics (second-line),
    • α-agonists (third-line).
  • Other treatments for stress incontinence:
    • Topical estrogen for atrophic urethritis.
    • Periurethral injection of bulking agents (e.g., collagen) to improve urethral closure.
    • Artificial urinary sphincters for post-prostatectomy stress incontinence.
    • Surgery as a last resort.

Urinary Catheterization

• Used for chronic bladder-emptying difficulty, elevated post-void residual volume (PVR), and severe illness.
• Can be used in bedridden patients with chronic urinary incontinence.

Sacral Nerve Stimulation

• For urge incontinence.

Botulinum Toxin

• Used for patients with detrusor overactivity.

This quiz explores the effects of aging on various body systems, particularly focusing on the nervous system and special senses. It covers how aging impacts vision, smell, and hearing, as well as cognitive functions and physical capabilities. Prepare to examine the complex changes that occur as individuals age.