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CHAPTER THREECHAPTER THREEPhysical ChangesPhysical Changes
Why Do We Age?—Biological Theories
Rate-of-Living Theories• Limited energy to expend in a lifetime • Excess calories may reduce lifespan
Cellular Theories
• Limited number of times a cell can divide (Hayflick limit)– Telomeres (tips of chromosomes) become shorter with
each cell division • Cross-linking
– Tissue becomes stiffer with age
• Free radicals– Reactive chemicalscause cellular damage
Programmed Cell Death Theories
• Aging may be programmed into genetic code– Cells may be pre-programmed to self-
destruct
• Changes in Skin– Why does our skin wrinkle?
• Four-step process– Outer layer becomes thinner
because of cell loss– Collagen fibers lose flexibility– Elastin fibers lose ability to keep
skin stretched out– Underlying fat layer diminishes
– Environmental factors affecting skin
• Sun exposure• Smoking
– Other skin changes• Pigment-containing cells decrease• Age spots, moles• Varicose veins
Changes in the body that occur with age
Changes in the Hair– Hair loss caused by destruction of
germ centers that produce hair follicles
– Graying caused by cessation of pigment production
– Other hair changes• Males do not lose facial hair.• Females gain facial hair.
– Caused by hormonal changes
Changes in the body that occur with age
• Attributes of the aging voice:– Lowering in pitch– Increased breathlessness and trembling– Slower and less pronounced pronunciation – Decreased volume
• May be due to normative changes or poor health
Changes in the body that occur with age
• Decrease in height with age– Between mid-50s and mid-70s men lose about 1
inch and women 2 inches– Compression of the spine – Changes in posture
• Weight gain then loss– Usually a weight gain between 20 and 50– Usually a weight loss throughout the older
years– How different between men and women?
• Research suggests that one lives longer with a normal body weight
Changes in Body Build
• Muscles– Strength loss: age 70, up to 20%; age 80, up to 40%– No difference in the rate of muscle change between men
and women
Changes in Mobility
Changes in Mobility
• Bones– Loss begins in
the late 30s, accelerates in the 50s, and slows in the 70s
– Osteoporosis: loss of bone mass; leading cause of broken bones in older women
Changes in Mobility
• Joints– Osteoarthritis occurs when the bones beneath cartilage
become damaged– Rheumatoid arthritis is a disease of the joints
Changes in Vision• Structural changes in the eye
– Decreased ability to allow light into the eye– Adaptation between light and dark is slower– Presbyopia: difficulty focusing on close objects– Cataracts: spots develop on the lens, clouding
vision– Glaucoma: pressure in the eye may result in
loss of peripheral vision
Changes in Vision
• Retinal Changes– Macular degeneration: loss of receptor cells
in the eye– Diabetic retinopathy: may result in blindness
Changes in Hearing
• Due to normative age-related changes• Due to loud environment
– Presbycusis: Reduced sensitivity to high-pitched tones Hearing Loss Simulation - YouTube
• With age there is a loss of touch only on smooth skin of the hand
• Temperature regulation is sometimes more difficult in older adults
Changes in Somesthesia
• Kinesthesis is ones sense of where they are in space; involving muscles and joints
• Vestibular system is in the inner ear and helps with balance and movement– Fear of falling, dizziness, vertigo increase with age
• Environmental hazards– Loose rugs– Slippery floors– Hip protection
• Tai Chi—– Helps maintain banlance
Changes in Balance
• Taste receptor cells do not change in quantity across the lifespan
• Taste is dependent on smell• Smell diminishes after age 60 and
sometimes can be used to diagnose Alzheimer’s disease
Changes in Smell and Taste
• Underlying cause of diminished capacity– Accumulation of fat deposits– Stiffening of the heart muscle
Changes in the Cardiovascular System
• Congestive heart failure: cardiac output declines, heart gets larger—most common cause of hospitalization for those over 65
• Angina pectoris: chest pain due to insufficient oxygen supply to heart
• Myocardial infarction (MI): blood supply is severely reduced; pain may or may not be present
Cardiovascular Disease: #1 cause of death
• Atherosclerosis: build-up of fat deposits; may lead to CVA
• Cerebrovascular accident (CVA) or stroke: blood flow to brain is cut off
• Hypertension: high blood pressure
Cardiovascular Disease: #1 cause of death
• Respiratory Diseases– Chronic obstructive pulmonary disease (COPD), includes:
• Emphysema– Destruction of membranes around the air sacs in the lungs– 82% self-induced by smoking
• Chronic bronchitis– Bronchial passageways become irritated by dust, fumes, air pollution,
etc.– More common with people over 45
Changes in the Respiratory System
Changes in the Female Reproductive System
– Perimenopause• Transition to menopause involving changes in reproductive
organs and sexual functioning• Genital organ change begins in the 40s
– Menopause• The point at which the ovaries cease to release eggs
– Hormone Replacement Therapy (HRT) – No physiological reason why most women cannot
continue sexual activity into old age.– Climacteric: the transition from reproductive to non-
reproductive years
Changes in the Male Reproductive System– Unlike menopause, no event to mark male reproductive changes
• Gradual decline in testosterone levels• Decrease in sperm production (30% between 30 and 60)
– Prostate cancer a real threat– Impotence/Erectile Dysfunction: treatable with drugs such as Viagra
• Psychological Implications– For healthy adults, sexual activity is a lifelong option.