How does this apply to humans?
Is there enough biological similarity between hibernating mammals and humans to use this as
whether the number of calories one eats has an influence on aging.
controlled experimental evidence with humans is lacking,
Okinawans, who eat only 60% of the normal Japanese diet, have 40 times as many centenarians
Okinawan incidence of cardiovascular disease, diabetes, and cancer is half that of the rest of
hormonal regulatory system's adap¬ tation to stress
stress per se does not cause aging, body's ability to deal with it undergoes significant decline with age.
we still do not know enough about the connection between the experience of stress, its effects
on the immune system, and subsequent disease
Definiton: Cells grown in laboratory culture dishes undergo only a fixed number of divisions
before dying, the number of possible divisions dropping depending on the age of the donor
organism; Hayflick limit.
Evidence suggests that the tips of the chromosomes, called telomeres, play a major role
telomerase is needed in DNA replication to fully replicate the telomeres.
telomerase normally is not present in cells,
Page 4 Definiton: cross-linking, certain proteins in human cells interact randomly and produce mole¬
cules that are linked in such a way as to make the body stiffer
make up roughly one-third
protein in the body,
this process is important to remember in the treatment of diseases such as hypertension.
cross-linking by itself is not an adequate explanation of aging,
significant effect on health and functioning in later life.
Definiton: free radicals, highly reactive chemicals produced randomly in normal metabolism free radicals may cause cellular damage,
in turn impairs the functioning
Definiton: antioxidants, prevent oxygen from combining with susceptible molecules to form free
ingesting antioxidants postpones the appearance of age-related diseases such as cancer,
cardiovascular disease, and immune system dysfunction
no evidence that taking antioxidants actually increases the life span
What if aging were programmed into our genetic code?
now believe that such losses may be part of a master genetic program Programmed cell death appears to be a function of physiological processes,
innate ability of cells to self-destruct,
ability of dying cells to trigger key processes in other cells.
It is possible
the changes we examine throughout this text are the result of a genetic program.
Implications of the Developmental Forces
the biological the¬ ories provide ways to describe the biological forces.
integrate the biologi¬ cal forces with the psychological, sociocultural, and life-cycle forces. changes in body systems and diseases are influenced by these other factors.
diagnosis and treatment of health-related concerns must also include many perspectives.
results of all these examinations must be placed in the context of the overall life span.
how we feel about aging;
positive feelings about the signs of aging are related to positive self-esteem.
How easily we move our changing bodies in the physical environment
If we cannot get around, we must depend on others, which lowers our self-esteem and sense of
Changes in Skin, Hair, and Voice Wrinkling
outer layer of skin becomes thinner
lose much of their flexibility,
Third, elastin fibres in the middle layer of skin lose their ability to keep the skin stretched out, Finally,
underlying layer of fat,
A major cause of
wrinkles is exposure to ultraviolet rays from the sun
older adults' skin thinner and drier,
makes it less effective at regulating heat or cold,
makes it more susceptible to cuts, bruises, and blisters.
Page 7 colouring of light-skinned people undergoes additional changes with age.
Changes in the Hair.
Gradual thinning and grey¬ ing of the hair of both men and women occur inevitably with age,
Men usually do not lose facial hair
Changes in the Voice.
Age-related changes in one's voice include lowering of pitch, increased breathlessness and
trembling, slower and less precise pronunciation, and decreased volume.
changes in the larynx
and the respiratory system cause of these changes
Changes in Body Build
a decrease in height
fluctuations in weight.
Weight gain in middle age followed by weight loss in later life is common.
weight gain tends to be around the abdomen, women,
weight gain tends to be around the hips,
differences may be caused by changes in lifestyle and dietary habits.
amount of muscle tissue in our bodies declines with age,
age 70 the loss is no more than 20%.
rate of change increases.
age 80 the loss in strength is up to 40%, muscle endurance also diminishes with age but at a slower rate.
men in later life continue to show greater muscle strength overall than do women,
Normal aging is accom¬ panied by the loss of bone tissue throughout the body.
The gender difference in bone loss is important.
women lose bone mass approximately twice as fast as men.
less bone mass
depletion of estrogen speeds up bone loss.
bone changes cause
likelihood of fractures
hollow, porous bones break more easily.
more likely to be clean fractures that are difficult to heal.
Definitonloss of bone mass and increased porosity create bones that resemble laced
Page 9 Osteoporosis
leading cause of broken bones in older women
appears more often in fair-skinned, thin, and smallframed women of European descent
the ability to engage in meaningful leisure activities added to the well-being of older women
relationship between dietary calcium intake and osteoporosis is controversial
calcium supple¬ ments after menopause
slow the rate of bone loss bene¬ fits
depend on the type of supplementa¬ tion
calcium citrate more effective
effects of supplementation
estrogen deple¬ tion affects bone loss
not fully understood, indirect
no estrogen receptors in bone tissue.
estrogen therapy must be continued indefinitely because bone loss speeds up as soon as the
therapy is stopped.
protective cartilage in joints shows signs of deterioration,
Definitondisease marked by gradual onset and progression of pain and disability, with minor
signs of inflammation
noticeable in late middle age osteoarthritis is a wear-and-tear disease.
usually affects the hands, spine, hips, and knees,
Definitonmore destructive disease of the joints that also develops slowly and typically affects
dif¬ ferent joints and causes different types of pain than osteoarthritis
pattern of morning stiffness and aching develops in the fingers, wrists, and ankles on both sides
symptoms often come and go in repeating patterns.
appearance of wrinkles, grey hair, fat, and the like can have major effects on a person's
selfconcept many women
use any available means to compensate for these changes.
at some point everyone takes on a distinctly old appearance. Losses in strength and endurance
in old age have much the same psychological effects as changes in appearance
can prove embarrassing and stress¬ ful.
older adults get stronger at the same rate as younger adults.
changes in the joints,
can severely limit move¬ ment,
reducing independence joint pain is very difficult to ignore or disguise,
older adults use a wide range of adaptive behaviours to cope.
For all fractures, the recovery period is much longer than that for a younger adult.
one of the first noticeable signs of aging,
normative, age-related changes have profound and pervasive effects on people's everyday lives
Structural Changes in the Eye.
decrease in the amount of light that passes through the eye, need for more light to do tasks such as reading.
our ability to adjust to changes in illumination,
time it takes for both types of adaptation increases with age
lens becomes more yellow, causing poorer colour discrimination
lens's ability to adjust and focus declines
the time our eyes need to change focus from near to far
Page 13 some people experience diseases caused by abnormal struc¬ tural changes.
second major family of changes
changes in the retina.
Macular degeneration involves the progressive and irre¬ versible destruction of receptors from
any of a number of causes.
loss of the ability to see details;
Roughly 1 in 5 people over age 75, especially smokers and women, have macular degen¬
leading cause of functional blindness in older adults. Definitonthe ability to see detail and to discriminate different visual patterns,
acuity is especially noticeable at low light levels
Psychological Effects of Visual Changes.
age-related changes in vision affect every aspect of older adults' daily lives.
some of the universal changes,
can be corrected easily
Older adults may also have trouble seeing some fine facial details. Some may react to these changes by simply avoiding the kitchen or listening to their favourite music,
or avoid social contact out of fear
1996a).Visual prob¬ lems also increase vulnerability to falls
one of the most wellknown normative changes with age
Loud noise is the enemy of hearing at any age.
you can do serious damage to your hearing with short exposure too.
Definitonreduced sensitivity to high-pitched tones,
Definitonoccurs earlier and more severely than the loss ofsensitivity to low-pitched tones Page 15
Men typically have greater loss than women,
may be because of differential exposure
gradual at first but accelerates during the 40s,
Presbycusis results from four types of changes in the inner ear
Page 16 mechanical,
major role in social communication,
progressive loss could have an equally important effect on social adjustment.
can cause numerous adverse emotional reactions,
may negatively affect how they feel about interpersonal communication.
hearing impairment is under-diagnosed in older adults.
technology continues to improve, none of these devices can duplicate our original equipment,
Page 17 Somesthesia.
it takes more pressure with age to feel a touch on the smooth
touch sensitivity in the hair-covered parts of the body is maintained into later life
Older adults often report that they have more trouble regulating body temperature so that they
pain is not well assessed, diagnosed, or managed in older adults
particular challenge is the assessment of pain in people with cognitive impairment.
Definitonsense of body position,
Definitonkinesthesis. Definitoninvolves sensory feedback about two kinds of movements:
Definitoninstigated by something (or someone) else,
Definitonvoluntary, as in walking.
Losing bodily sensations can have major implications; loss of sexual sensitivity and changes in
the ability to regulate one's body temperature affect the quality of life. How a person views
these changes is critical for maintaining self-esteem.
We get informa¬ tion about balance from the vestibular syst