Aging is the study of life changes that occur as one grows older across biological, psychological, social, legal, and functional domains. Common aging changes include declines in processing speed and working memory, sensory and perceptual changes, and changes in brain, heart, lungs, kidneys, muscles, bones and skin. The immune system also declines with age, making older adults more susceptible to infection. Overall, aging results from both primary aging due to genetic factors and secondary aging due to environmental influences and disease.

1. Aging Concept
• Aging is a pattern of life changes that oc
as one grows older.
• Gerontology is the study of individual a
collective aging processes
– Biological age
– Psychological age
– Social age
– Legal age
– Functional age

2. Normal Aging
 Who is old?
• Biological and psychological aging changes usually oc
gradually, over years or decades, and as a result, ther
single age at which people in general can be said to b
• Commonly people older than 65 are called ‘OL
• Gerontologists often draw finer chronological demarca
• Young-old: <75
• Old-old: >75
• Oldest-old: >85

3. Cognitive Abilities in Later Life: A Pr
Resource Model
• Declines in three fundamental cognitive-processing
resources:
1.Processing Speed: reduced speed of information pro
and response- most predictable
2.Working Memory: refers to short-term retention and
manipulation of information held in conscious memory
type of “online” cognitive processing.exa. Examples include
consciously recalling a telephone number long enough to write it
3.Sensory and Perceptual changes: decrements in v
auditory acuity and other perceptual changes.

4. Explanations of Cognitive Agi
Changes
• Neuropathological and neuroimaging studies: changes in br
aging
• generalized atrophic and white matter changes as well as r
specific variations in the extent of cell loss
• Affected areas: Within the cortex, the prefrontal lobe
disproportionately affected, Hippocampus and entorhina
are affected but data are conflictual
• Subcortical monoaminergic cell populations, are also subjec
prominent decline in aging
• Spared areas: Temporo-parietal association areas
• Areas in which there is relative sparing with age: the glob
pallidus, the paleocerebellum, the sensory cortices, and the

5. General Aging Trends

6. General Aging Trends

7. Factors That Influence Cognitive

8. Personality and Emotional Ch
1. Coexisting Stability and Change:
• Developmental optimism: subjective growth in person
2. Influences on Adult personality: three developme
forces:
- Social clock
- grand adaptive strategy: individual’s desire
in personal past and present
- genetic factors:A study of elderly twins and multigenerational
families found a genetic contribution to negative affect but not t
positive affect
• Eriksonian Psychosocial developmental stages
• Late adulthood: integrity vs despair
• Virtue: wisdom

9. Personality and Emotional Ch
3. Personality and Perceptions of Health: Older adults’ p
of their health have been linked to a variety of objective he
outcomes, including mortality
• Depression: affects subjective health concerns
• Neuroticism: is inversely associated with self-perceptions
health
• Extraversion: is positively associated
these associations were stronger among persons age 75 and older than am
in their 60s and early 70s (Duberstein et al. 2003)
4. Emotions, Coping, and Well-Being:
Emotions: old age is an emotionally rich and complex phase
the salience of emotion, increases in later years
have better control over emotions than do younge

10. Personality and Emotional Ch
• Coping: older people tend to cope with stressful events in differe
• rely more on emotion-focused forms of coping, as opposed to act
problem-solving approaches
• Emotion-focused coping is more
passive than confrontational,
individual than interpersonal, and
is oriented toward control of distressing feelings rathe
alteration of stressful situations
• Wellbeing: Specific stressful events have less of an effect on su
well-being in old age than does attainment of personal goals or th
of physical disability
• A model relates resilience in old age (i.e., maintaining adaptiv
in the face of stress and recovering from adversity) to a process o
selective optimization, in which goals are reshaped to fit curre
limitations and environments, and resources are spared for perso
important activities that sustain self-esteem

11. Social Context of Aging
• Old age is accompanied by role change and, often, role loss
• expect transformations in occupational, family, and commu
roles
1. Education, Work, and Financial Status
• Education: changes perception and thinking about life and
• Work: lack of work, loss of income, continuous work help p
as well as financially
• Financial status: retirement, loss of income
• Source of income: pension plans, social security, personal earnings,
incomes
2. Marriage and Widowhood:
3. Retirement and Grandparenthood:
4. Extended Families, Friends, and Group Involvement:

12. Biological Aging
• What is Aging?
• definition of aging was proposed by Birren and Zarit (1
“Biological aging, senescing, is the process of change in the orga
which over time lowers the probability of survival and reduces th
physiological capacity for self-regulation, repair and adaptation to
environmental demands”
• Modern gerontologists distinguish
• Primary aging, which is postulated to reflect an intrinsic, presum
genetically preprogrammed limit on cellular longevity,
• Secondary aging, which is due to the accumulated effects of
environmental insult, disease, and trauma.
• Primary aging seems to account for the relatively constant max
span observed in almost all animal species studies,
• secondary aging explains much of the variability among individ
members of a species.

13. Theories of aging
• Aging theories can be divided into
• Organ-based,
• Physiological,
• Genomic hypotheses
• Organ-based theories hypothesize that human aging results fr
incremental loss of organ function driven by the immune system
alterations in neuro-endocrine function of the CNS.
• Physiological theories suggest that toxic levels of cellular was
accumulate over time resulting from free radical damage, incapa
of neuroprotective mechanisms, or cross-linkage of vital molecule
example, collagen, deoxyribonucleic acid (DNA), and vital protein

14. Genomic Hypothesis
• hypothesize aging as the consequence of somatic mut
multiple genetic errors, or programmed cell death
• Evidence that the “Hayflick phenomenon” is under
control includes
1) a fair correlation between the doubling limit and the maximum species-s
span of the cell donor and
2) a reduced doubling limit in cells cultured from patients with genetic dise
accelerated aging
• The precise mechanism underlying the observed limits on norma
division is not completely known, but several lines of evidence po
telomeric shortening as at least one likely “clock” mechanism
• A conceptual disagreement exists between theories that human sene
brain alterations result from disuse versus overuse (i.e., the “use it
theory) and those that attribute aging to cumulative damage (i.e., t
“wearing it out” theory)

15. PRIMARY AGING: STRUCTUR
AND FUNCTIONAL CHANGE

16. Observed Changes in the Hea
• Deposits of the "aging pigment," lipofuscin accumulat
• The valves of the heart thicken and become stiffer.
• The number of pacemaker cells decrease and fatty
tissues increase around the SA node. These changes m
in a slightly slower heart rate
• A slight increase in the size of the heart, especially the l
ventricle, is common. The heart wall thickens, so the am
blood that the chamber can hold may actually decrease
• The heart may fill more slowly. To compensate, elder
demonstrate a doubling of percent atrial contribution to

17. EFFECT OF CHANGES
• Under normal circumstances, the heart continu
adequately supply all parts of the body. Howev
aging heart may be slightly less able to tolerat
increased workloads.
• Examples of stressors include: illness, infection
emotional stress, injuries, and extreme physica
exertion.

18. Observed Changes in the Vess
• Blood vessels
– Arteries
» thickening & stiffening in the media of large ar
though to be caused by collagen cross-linking
» smaller arteries may thicken/stiffen minimally; their
ability to dilate & constrict diminishes significantly
– Veins
» age-related changes are minimal and do not impede
normal functioning

19. Observed Changes in the Vess
• The aorta becomes thicker, stiffer, and less flexible. This makes
pressure higher resulting in LV hypertrophy.
• Increased large artery stiffness causes a fall in DBP, associated
continual rise in SBP. Higher SBP, left untreated, may accelerat
artery stiffness and thus perpetuate a vicious cycle.Circulation. 1997;96:308-315
• Baroreceptors (stabilize BP during movement/activity) become
sensitive with aging. This may contribute to the relatively comm
finding of orthostatic hypotension.

20. Observed Hematologic Chang
• A decrease in total body water is observed with aging.
volume therefore decreases.
• The number of red blood cells are reduced, but not
significantly.
• Most of the white blood cells stay at the same levels, b
lymphocytes decrease in number and effectiveness

21. Observed Hematologic Chang
• Overall, cell counts and parameters in the
peripheral blood are not significantly differen
from in young adult life.
• However, the cellularity of the bone marrow
decreases moderately. For example, 30%
cellularity on an iliac crest biopsy (which wou
very low for a young adult) is not unusual in a
older person.

22. The Immune System

23. Age and the Immune System
• The efficiency of the immune system declines with age, bu
variable among persons.
• Nonspecific defenses become less effective
• The ability of the body to make antibodies diminishes.
• Autoimmune disorders are increased in older adults. Not everyo
believes that the increased incidence of autoimmune disease is
expected part of aging.
– but all acknowledge the increase in findings of positive rheumatoid
anti-nuclear antibody, and false-positive syphilis screens in healthy
adults.
• The thymus gland (which produces hormones that activate T cel
atrophies throughout life.
• The peripheral T-cells(J. Immunol. 144: 3569, 1990)proliferate much less exuberantly in
old age.

24. The Result….
• Common infections are often more seve
with slower recovery & decreased chan
of developing adequate immunity.

25. Observed Changes in the Lun
• The number of cilia & their level of activity is
reduced.
• Glandular cells in large airways are reduced.
• Decreased number of nerve endings in larynx.
• The cough reflex is blunted thus decreasing th
effectiveness of cough.
• Decreased levels of secretory IgA in nose & lun
decreased ability to neutralize viruses.
• The number of alveoli do not change significa

26. Observed Changes in the Lun
• The number of FUNCTIONAL alveoli decre
as the alveolar walls become thin, the av
enlarge, are less elastic.
• Decreased elasticity of the lungs may
to collagen cross-linking.
• The loss of elasticity accounts for "senile
hyperinflation"; unlike in smokers, there
little or no destruction of the alveoli.

27. Observed Changes in the Lun
• Combine less functional alveoli with sligh
thickened capillaries decreased surface
area available for O2-CO2 exchange lower O2
to supply vital organs, especially in settin
acute respiratory illness.

28. Observed Changes in the Lun
• The respiratory muscles lose strength &
endurance.
• There is increased stiffness of chest wa
decreased compliance).
• Pulmonary vasculature becomes less el
pulmonary artery thickens & enlarges
increased resistance to blood flow in lun
 increased pulmonary artery pressure

29. Observed Changes in the Kidn
• Renal blood vessels become smaller & thicke
reducing renal blood flow.
• Decreased renal blood flow from about 600m
(age 40) to about 300ml/min (age 80)
• Kidney size decreases by 20-30% by age 90.
– This loss occurs primarily in the cortex where the
glomeruli (# of gloms decrease by 30-40% by age
located.
• Decreased GFR. Typically begins to decline a
about age 40. By age 75 GFR may be about
less than young adult. Current research sho
that this is not true for all elders, however.

30. Observed Changes in the Kidn
• There is a decline in the number of renal tubu
cells, an increase in tubular diverticula, & a
thickening of the tubular walls decreased ability
to concentrate urine & clear drugs from the bo
• Overall kidney function, however, remains nor
unless there is excessive stress on the system.

31. Observed Changes in the Bladder & S
• The muscular ureters, urethra, & bladde
lose tone & elasticity. The bladder may
retain urine.
– This causes incomplete emptying.
• Decline in bladder capacity from about 5
600mL to about 250ml less urine can be
stored in the bladder.
– This causes more frequent urination.
– The warning period between the urge and
actual urination is shortened or lost as one

32. Observed Changes in the Musculoske
System…..
• Muscles
– Sarcopenia (↓ muscle mass & contractile force) oc
with age. Some of this muscle-wasting is due to
diminished growth hormone production(NEJM 323: 1, 1990),
– exactly how much is due to aging versus disuse is u
– Sarcopenia is associated with increased fatigue & ri
falling (so may compromise ADLs).
– Sarcopenia affects all muscles including, for examp
respiratory muscles (↓ efficiency of breathing) & GI
(constipation).

33. Observed Changes in the Musculoske
System…..
• Bone/Tendons/Ligaments
– Gradual loss of bone mass (bone resorption > bon
formation) starting around age 30s.
– Decreased water content in cartilage
• the “wear-&-tear” theory regarding cartilage destruction &
activity doesn’t hold up as osteoarthritis is also frequently
sedentary elders.
– Decreased water in the cartilage of the intervertebr
results in a ↓ in compressibility and flexibility. This
be one reason for loss of height.
– There is also some decrease in water content of ten
ligaments contributing to ↓ mobility.

34. Observed Changes in the GI Tr
• Some sources claim that one can expect atrophy & decrease in the num
(especially) anterior (salty/sweet) taste buds, but this is controversialNEJM 322: 438, 1990
• Basal and maximal stomach acid production diminish sharply in old a
same time, the mucosa thins. Very little seems to happen to the small b(J. Clin. Path.
45: 450, 1992)
• Decline in number of gastric cells decreased production HCL (an acidic
environment is necessary for the release of vitamin B12 from food sour
• Decrease in amount of pancreatic enzymes without appreciable chan
CHO, or protein digestion.
• Diminished gastric (eg pepsinogen) & pancreatic enzymes result in a hi
the absorption of other nutrients like iron, calcium, & folic acid.
• Hepatic blood flow, size & weight decrease with age. Overall funct
is preserved, but may be less efficient in the setting of drug overload.
• Decreased tone in stomach & intestines result in slower peristalsis constipation.

35. Observed Neurologic Change
• There is neuronal loss in the brain throughout life (the am
location varies).J. Ger. 47: B26, 1992.
– Loss is chiefly gray matter not white matter
– there is some evidence that although some neuronal loss occur
age, many neurons have ↑ dendrite growth which may (at leas
partially) compensate for neuronal loss in some areas of the br
• Slowed neuronal transmission
• Loss of brain weight and volume in most studies
• Loss of dendritic arbor, with reduced interneuronal conne
• Interneuronal accumulation of lipofuscin and loss of organ
• Neurofibrillary degeneration of neurons; accumulation of
plaques, especially in hippocampus, amygdala, and fronta

36. Observed Neurologic Change
• The lens of the eye loses fluid and becomes les
flexible, making it more difficult to focus at the
range.
• Dry eyes
• Changes in sleep cycle: takes longer to fall asle
total time spent sleeping is less than their you
years, awakenings throughout the night, increa
frequency of daytime naps
• Sense of smell markedly decreases

37. Neurobiology of aging

38. Neurobiology of aging

39. Observed Hair Changes
– Men:
• men loose the hair about their temples during their 20s
• hairline recedes or male pattern baldness may occur
• increased hair growth in ears, nostrils, & on eyebrows
• loss of body hair
– Women
• Usually do not bald, but may experience a receding hairl
• hair becomes thinner
• Increased hair growth about chin & around lips
• loss of body hair

40. Observed Skin Changes - Epiderm
• The number of epidermal cells decrease
10% per decade and they divide more s
making the skin less able to repair itsel
quickly.
• Epidermal cells become thinner making
skin look noticeably thinner.
• Changes in the epidermis allows more fl
to escape the skin.

41. In Between
• The rete-ridges of the dermal-epidermal
junction flatten out
– making the skin more fragile and making it e
for the skin to shear.
– This process also decreases the amount of
nutrients available to the epidermis by decre
the surface area in contact with the dermis.
= slower repair/turnover

42. Observed Skin Changes - Derm
These changes cause the skin to wrinkle an
• The dermal layer thins
• Less collagen is produced
• The elastin fibers that provide elasticity w
out.
---------
• ↓ function of sebaceous & sweat glands
contribute to dry skin

43. Observed Skin Changes – Sub
• The fat cells get smaller
– This leads to more noticeable wrinkles and
sagging

44. Endocrine System
• Because the endocrine system is so com
interrelated it is difficult to discern the eff
of aging on specific glands

45. Age-Related Changes in the Endocri
System
• In most glands there is some atrophy &
decreased secretion with age, but the cli
implications of this are not known.
• What may be different is hormonal action

46. Age-Related Changes in the Endocri
System
Hormonal alterations are variable & gende
dependent
• Most apparent in:
– glucose homeostasis
– reproductive function
– calcium metabolism
• Subtle in:
– adrenal function
– thyroid function

47. Age-Related Changes in the Reproduc
System
Women
• The “climacteric” occurs (defined as the period during with reproductive
decreases (ie, ovarian failure) then finally stops = loss of estrogen & pro
FSH & LH ↑↑). This is also described as the transition from perimenopa
40s) to menopause.
• thinning & graying of pubic hair
• loss of subQ fat in external genitalia giving them a shrunken appearance
• ovaries & uterus decreases in size & weight
• skin is less elastic + loss of glandular tissue gives breasts a sagging app
• other physical changes may include hot flashes (can cause sleep depriva
occur at night), sweats, irritability, depression, headaches, myalgias. Se
variable. The symptoms are typically present for about 5 years
• atrophy of vaginal tissues due to low estrogen levels = thinning & dryne

48. Age-Related Changes in the Reproduc
System
Men
• Testosterone decreases, testes become softer & smalle
• Erections are less firm & often require direct stimulatio
retain rigidity
• Though fewer viable sperm are produced & their motil
decreases, men continue to produce enough viable sp
fertilize ova well into older age.
• Less seminal fluid may be ejaculated
• they may not experience orgasms every time they hav
• the prostate gland enlarges; this often results in comp
of the urethra which may inhibit the flow of urine.