Study guide: Physiological Changes in Older Adults

📋 Course Outline

1. Definitions and Types of Aging
2. Microbiological and Macrobiological Theories
3. Brain and Nervous System Changes
4. Neurological Disorders in Older Adults
5. Sensory System Changes
6. Circulatory and Respiratory Changes
7. Chronic Disease and Health Risks

📖 1. Definitions and Types of Aging

🔑 Key Concepts & Definitions

• Biological aging: López-Otín dkk. - López-Otín et al. (2023) define aging as the progressive decline of physiological function at cellular and molecular levels, marked by accumulated genetic damage, loss of protein balance, and mitochondrial dysfunction, which increase vulnerability to disease and death.
• Global health perspective on aging: The WHO (2021) defines aging as the accumulation over time of molecular and cellular damage that gradually reduces physical and mental capacity, increases disease risk, and ultimately leads to death.
• Primary aging: The universal change that occurs with increasing age and is not caused by disease or environmental influences.
• Secondary aging: Change involving the interaction of primary aging processes with environmental influences and disease processes.

📝 Essential Points

• Aging begins in early adulthood.

💡 Memory Hook

Primary aging is universal; secondary aging involves environment and disease.

📖 2. Microbiological and Macrobiological Theories

★ Must-know

• In the microbiological theory, aging cells cause their molecules to connect, adhere, and accumulate, potentially stopping vital biochemical cycles and producing further damage that disrupts cell function.

• With age, the immune system diminishes in its ability to recognize and fight bacteria and viruses, making older adults more susceptible to infection.

• DHEA production begins to decline in a person's 30s and may stop; the source associates this decline with increased breast cancer risk in women and heart attack risk in men.

Further detail

• Older adults with comorbidities are more vulnerable to viruses.

• The brain, especially the hypothalamus and pituitary gland, plays an important role in hormone release.

• The nervous and endocrine systems regulate homeostasis and monitor the heart, lungs, kidneys, and other organs; aging also reduces the function of the body's supporting organs.

💡 Memory Hook

Cellular damage accumulates → vital biochemical cycles can be disrupted.

📖 3. Brain and Nervous System Changes

★ Must-know

• Older adults lose some neurons, the basic units of nerve cells.

• Brain volume shrinks with age, especially in the prefrontal cortex, associated with executive function, and the hippocampus, associated with memory.

• Nerve transmission slows with age, affecting processing speed.

Further detail

• Despite the loss of some neurons, the brain can continue to function effectively, and not all older adults experience dramatic damage to brain cells.

📖 4. Neurological Disorders in Older Adults

🔑 Key Concepts & Definitions

• Dementia: A decline in cognitive function that affects memory, thinking, and behavior; Alzheimer's disease is its most commonly encountered type.
• Alzheimer's disease: The most common type of dementia that gradually impairs short-term memory, thinking ability, and personality.
• Stroke: A stroke occurs when blood flow to the brain is blocked or a blood vessel ruptures, and it can cause sudden paralysis or speech disorders.
• Parkinson's disease: A nervous system disorder that damages movement control and is characterized by tremor, body stiffness, and increasingly slow steps.
• Delirium: A sudden, temporary decline in mental function marked by severe confusion and difficulty focusing, often triggered by infection, medication side effects, or other physical illness.
• REM sleep behavior disorder: A disorder involving acting out dreams during sleep, such as shouting or kicking, and which can be an early sign of neurodegenerative disease.

📖 5. Sensory System Changes

★ Must-know

• Visual decline begins in middle adulthood; the lens loses elasticity and becomes more sensitive to light, adaptation to darkness takes longer, the visual field narrows, and stronger stimuli are needed when objects are farther from the visual field.

• Age-related deterioration of the cochlea reduces hearing ability, and in severe cases a person may hear only murmurs.

• Atrophy of taste buds and reduced regeneration of olfactory nerves diminish taste and smell sensitivity and can reduce appetite.

Further detail

• The pain threshold tends to be higher in older adults, who may consequently be less sensitive to pain and more tolerant of injuries and illness.

📖 6. Circulatory and Respiratory Changes

📝 Essential Points

• The amount of blood pumped by the heart decreases with age.

• Blood pressure may increase with age because of disease, obesity, anxiety, hardening of the blood vessels, or insufficient exercise.

• With age, lung capacity and lung elasticity decrease, the chest shrinks, and the diaphragm weakens.

📖 7. Chronic Disease and Health Risks

🔑 Key Concepts & Definitions

• Chronic disease: A disease that develops gradually over a long period, often beginning in early or middle adulthood.

★ Must-know

• Older adults have high morbidity and face a threat of mortality.

📌 People of all ages can face acute illness and environmental stressors, but older adults have a greater risk.

Further detail

• Examples of chronic diseases include:
  • arthritis
  • hypertension
  • heart disease
  • diabetes
  • asthma
  • osteoporosis