Chapter 17: Physical Development in Late Adulthood

Lifespan

Maximum number of years an individual can live 

• 120 to 125 years of age 

• Increase life expectancy by average of 30 years

Life expectancy

Number of years that the average person born in a particular year will probably live (e.g., 78.8 years) 

• Differs for various ethnic groups, genders

Ages 

Philippines: 66.4 years

Worldwide: 71.3 years

Japan: 84.5 years

Mortality

Women outlive women in virtually all species

• Female estrogen protects from arteriosclerosis

• Additional X chromosome is associated with more antibody production

• Social factors: health attitudes, habits, occupation, lifestyles

Lifestyles

Men: lung cancer and emphysema (heavier smokers than women)

Women: Alzheimer's, hypertension related problems

Religion promoted lifestyle: vegetarian

Life expectancy in the philippines

During the 2020 census: 65 years and over accounted for 5.4% of the total population 

2050, peak: 12% of Filipinos aged 65  years and older

Centenarians

100 years old

• in the philippines: Give filipino senior citizens under extended centenarians act

Super centenarians

110-119 years old

Compression of morbidity

Process of staving off high mortality chronic diseases until much later ages than usual

• Illnesses come up later 

• Older you get, later onset of disease

What helps longevity (okinawa)

• Diet: grains, fish, vegetables, light on meat, eggs, dairy products

• Low stress lifestyle: doesn't stress much 

• Caring community: doesn't feel like they are useless 

• Activity: engage in activities like planting

• Spirituality: helps with meaning in life

Biological theories of aging

• Evolutionary theory of aging

• Genetic/ cellular process theories

• Hormonal stress theory

Evolutionary theory of aging

Natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults 

• Linked to reproductive fitness, present only in the early part of adulthood

Alzheimer disease

irreversible brain disorder that does not appear until late middle adulthood or late adulthood but if occurred earlier in development, it might have been eliminated many centuries age

Criticisms of evolutionary theory of aging

1. “Big picture” idea lead to the development of human traits and behaviors is difficult to refute or test because evolution occurs on a time scale that does not lend itself to empirical study

2. Failure to account for cultural influences

Genetic/ cellular process theories

Aging is explained by cellular maintenance requirements and evolutionary constraints

Sub theories under Genetic/ cellular process theories

• Cellular clock/ telomere theory

• Free radical theory

• Mitochondrial theory

• Sirtuin theory

• mTOR pathway theory

Cellular clock/ telomere theory

Cells can divide a maximum of 75 to 80 times

• Age makes cells less capable of dividing 

• Healthy centenarians has longer telomeres than unhealthy ones

Telomeres

DNA sequences that cap chromosomes

Telomere shortening contributes to aging

• Longer telomeres: healthy 

• Shorter telomeres: Alzheimer’s disease years before onset

• Exercise and a healthy diet can help slow telomere shortening

Injecting telomerase

• Telomerase is found in most cancer cells, so it may not promote healthy aging

• Researchers are developing gene therapies that inhibit telomerase to kill cancer cells while protecting healthy ones

Free radical theory

People age because normal metabolic processes within cells produce unstable oxygen molecules that ricochet around inside cells damaging DNA and cellular structures 

• Unstable oxygen molecules 

• Ricochet around cells, damage DNA and other cellular structures

• Lead to disorders like cancer, arthritis

Mitochondrial theory

Aging is caused by the decay of mitochondria 

• Decay is due to oxidative damage and loss of critical micronutrients supplied by the cell 

• Not known: is it the cause of aging or an accompaniment of aging

Sirtuin theory

Family of proteins linked to longevity, regulation of mitochondria functioning in energy, possible benefits of calorie restriction, stress resistance, lower rates of diabetes and cancer

• DNA repair and greater longevity: SIRT 1 SIRT 7 SIRT 6

mTOR pathway

Cellular pathway that involves the regulation of growth and metabolism

• Target of Rapamycin (TOR) in mammals 

  • Naturally derived antibiotic and immune system suppressant or modulator 

  • If rapidly, do quickly and die quickly also so need to be regulated, this is the role of rapamycin 

• Rapamycin has side effect like lymphoma

Hormonal stress theory

Aging in the body’s hormonal system can lower resistance to stress and increase likelihood of disease 

• Aging contributes to immune system deficits: infectious diseases in older adults 

• Extended duration of stress + diminished restorative process may accelerate effects of aging

The shrinking, slowing brain

Brain loses 5 to 10 percent of its weight between the ages of 20 and 90

Healthy aging: brain volume decreases to

• Shrinkage of neurons

• Lower number of synapses

• Reduced length and complexity of axon

• Reduced tree like branching in dendrites

• To a minor extent neuron loss (occurs in Alzheimer's disease more)

Prefrontal cortex

Shrink more with aging than other areas of the brain do, resulting in decreased working memory and slower motor behavior in older adults

Corpus callosum

Show declines as we age: in middle to late adulthood showing protracted decline in the mid to late 50s, followed by further decline in the 60s

Sensory regions of the brain

Including primary visual cortex, primary motor cortex, and somatosensory cortex are less vulnerable to the aging process

Slowing of function

Begins in middle adulthood and accelerates in late adulthood

• Affecting physical coordination and intellectual performance

Aging is linked to

• Demyelination  

• Reduction in synaptic functioning

• Decrease in production of some neurotransmitters

Neurotransmitters

Reduced synaptic functioning and decreased production neurotransmitters: ACh, Dopamine, GABA

Acetylcholine

Small declines in memory functioning (learning neurotransmitters) 

Dopamine

Problems in planning and carrying out motor activities (pleasure neurotransmitter)

GABA

Preciseness of signal sent to one neuron to another (calming neurotransmitter) 

• Decreases noise: less GABA, less preciseness 

Adapting brain

Activities that older adults engage in can influence brain development

Aerobic fitness

Greater volume in the hippocampus, which translates to better memory, higher cortical and hippocampal volumes

Possibility of the brain to generate new neurons

Neurogenesis: generation of new neurons 

• Hippocampius and olfactory bulb, function not yet identified

• Last for several weeks

Role of dendritic growth

Dendrites: receiving portion of neuron 

• Dendritic growth increased (40s to 70s not in 90s) 

• Might compensate for loss of neurons in 70s but not in 90s 

• Lack of growth due to environmental stimuli 

• Need research for changes in dendrites

Adaptive potential of delateralization

Lateralization: specialization of function in one hemisphere of the brain or the other 

• Older adults lateralize less, use both hemispheres to compensate

• Using both hemispheres may improve cognitive functioning

Physical appearance and movement

Wrinkles and age spots are the most noticeable changes

Risk of falling

Increases

• Half of older adults who fracture a hip from a fall die within 12 months often from pneumonia 

• PH: prevalence of hip fracture- 160 per 10,000 adults age 70+ 

• Walking, proprioceptive training help

Height

Shorter height with aging due to bone loss in their vertebrae

Weight

Occurs because of muscle loss, which also gives our bodies a “sagging” look

• Exercise and weight lifting can help slow the decrease in muscle mass, improve physical appearance, increase mobility, and reduce frailty

Gender in weight

Risk of falling in late adulthood increases with age and is greater for women than for men

Sensory development

• Vision 

• Hearing

• Smell and taste

• Touch and Pain

• Perceptual motor coupling

Vision

• Cognitive decline 

• Fewer contacts

• Engaging in less challenging social or leisure activities

Visual acuity

Ability to see shapes and distance in distance

• Visual processing of information declines in older adults

• Traced to reduction in quality or intensity of light reaching retina

Color vision

Decline with age in older adults as a result of the yellowing of the lens of the eye

• Occur in the green-blue-violet part of the color spectrum

• Older adults may have trouble accurately distinguishing between objects of closely related colors

Depth perception

Changes little after infancy until adults become older

• Difficult for an older adult to determine how close or far away or how high or low something is

Diseases of eye

• Cataracts

• Glaucoma

• Macular degeneration

Cataracts

Thickening of the lens of the eye that causes vision to become cloudy, opaque, and distorted

Glaucoma

• Damage to the optic nerve because of pressure created by a buildup of fluid in the eye 

• Treated with eye drops; can cause blindness if untreated

Macular degeneration

• Deterioration of the macula of the retina, which corresponds to the focal center of the visual field

• Peripheral vision may remain; leading cause of irreversible blindness in older adults; 

• Early treatment: Laser or experimental stem-cell therapy

Hearing

Age of older adults is important in determining the degree of decline

Hearing impairment

Impairments becomes an impediment usually in late adulthood

• Linked with declines in activities of daily living, cognitive functioning, language

Minimizing problems linked to hearing loss

Hearing aids and cochlear implants

Dual sensory loss (vision & hearing)

• Reduced social participation, less social support, increased loneliness

• Greater functional limitation, increased loneliness, cognitive decline, communication problems., more depressive symptoms

Smell and taste

Losses begin at about age 60 years

• Greater decline in sense of smell than tasteTouch and pain

Touch and pain

Detect touch less in the lower extremities

• Lower sensitivity to pain for lower intensity pain

Benefits of changes in touch and pain

Help adults to cope with disease and injury

Negative effects of changes in touch and pain

Mask injuries and illnesses that need to be treated

Perceptual Motor Coupling

Declines in perceptual-motor skills make driving harder for older adults.

• They often compensate by driving shorter distances, on safer routes, and during daylight

Improve driving safety

Cognitive training programs and education

Cardiovascular disorders

Increase in cardiovascular disorders in late adulthood

High blood pressure linked to

• Illness

• Obesity

• Anxiety

• Stiffening of blood vessels

• Stress

• Lack of exercise

Best predictors of earlier death in older adults with heart problem

Diminished exercise capacity and lack of walking

Lung capacity

• Drops 40% between the ages of 20 and 80 (even without disease)

• Diminished exercise capacity & lack of walking 

• Mediterranean diet lowered risk of CVD

Health problems

Probability of having some disease or illness increases with age

• Chronic diseases with a slow onset and a long duration are common in late adulthood

Common health problems in older adults in the ph 2019

• Hypertension

• Arthritis

• Cataracts

• Diabetes

• Angina

Causes of death in older adults in the ph 2021

• Ischemic heart disease

• Lower respiratory infections

• Stroke

• 5th is COVID19

Arthritis

Inflammation of the joints accompanied by pain, stiffness, and movement problems

• No known cure

Reducing arthritis

Medication, range of motion exercises, weight reduction, replacement of the crippled joint

Osteoporosis

Extensive loss of bone tissue

• Causes older adults to walk with stoop

Prevention of osteoporosis

Young & middle aged women: calcium, exercise, no smoking