Transcript PHYSICAL AGING PROCESS

PHYSICAL AGING
PROCESS
WHEN DOES OLD AGE BEGIN?
DEFINITION OF AGING
• Old and aging depends on the age
and experience of the speaker.
• Chronological age - number of years
lived
• Physiologic age - age by body
function
• Functional age - ability to contribute
to society
CHRONOLOGICAL
CATEGORIES
• Young-Old - (ages 65 - 74)
• Middle-Old - (ages 75 - 84)
• Old-Old - (age 85 and older)
FRAIL ELDERLY
Characteristics:
• Poor mental and physical
health
• Low socioeconomic status
• Predominantly female
• Possibly isolated living
conditions
• More and longer hospital
stays, and
• More money spent on
health care and drugs
PHYSICAL THEORIES
OF AGING
What causes the body to age?
PROGRAM THEORY
Cells replicate a specific number of
times and then die. Happens again,
and again in lab experiments.
ERROR THEORY
• The structure of DNA
is altered as people age
• Due to alterations,
DNA not read correctly
• Results in transcription
and translation
malfunction
• Results in aging/illness/
cancer directly, or
indirectly
CELLULAR THEORY
Normal wear and tear causes cells
to function improperly
FREE RADICAL THEORY
• Lipids in cell
membranes are exposed
to radiation or free
radicals
• Cell membrane
ruptures and cell dies
• In test tubes this
actually occurs
NUTRITIONAL MODEL THEORY
• If animal fed 50-60%
less than it eats on its
own - lives longer
• Assumption: Lean
mass, as opposed to
adipose tissue results in
greater health
COLLAGEN THEORY OF AGING
As we age, collagen in body ages
also. Causes hypertension and
other organ malfunctions
MUTATING AUTO-IMMUNE
THEORY
• Cells have normal functions - secrete
normal proteins
• As cells age - mutate and secretions
viewed as foreign by body
• Solicits immune response
• Shuts cell down
• Cause biological errors and entire
organ malfunctions
NEURO-AGING THEORY
• All cells undergo
nervous system
degeneration
• Results in changes in
hormonal release
• Leads to decline in cell
function
NONE OF THESE
THEORIES TOTALLY
ACCEPTED
Scientists hypothesize it might be
combination of several or all
PHYSIOLOGICAL AGING
OF THE HUMAN BODY
BY SYSTEMS
SKIN, HAIR, NAILS
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Loss of subcutaneous fat
Thinning of skin
Decreased collagen
Nails brittle and flake
Mucous membranes drier
Less sweat glands
Temperature regulation
difficult
• Hair pigment decreases
• Hair thins
EYES AND VISION
• Eyelids baggy and wrinkled
• Eyes deeper in sockets
• Conjunctiva thinner and
yellow
• Quantity of tears decreases
• Iris fades
• Pupils smaller, let in less light
• Night and depth vision less
• “Floaters” can appear
• Lens enlarges
EYES AND VISION CONT.
• Lens becomes less
transparent
• Can actually
become clouded
• Results in
cataracts
EYES AND VISION CONT.
• Accommodation decreases
• Results in presbyopia
• Impaired color vision, also especially greens and blues
• Because cones degenerate
EYES AND VISION CONT.
• Predisposed to glaucoma
• Increased pressure in eye
• Decreased absorption of
intraocular fluid
• Can result in blindness
EYES AND VISION CONT.
• Macular degeneration
becoming more frequent
• This is the patch of retina
where lens focuses light
• Ultimately results in blindness
• Reason for current increase in
this condition unknown
EARS AND HEARING
LOSS
• Irreversible, sensorineural
loss with age
• Men more affected than
women
• Called presbycusis
• Loss occurs in higher range
of sound
• By 60 years, most adults
have trouble hearing above
4000Hz
• Normal speech 500-2000Hz
RESPIRATORY SYSTEM
• Lungs become more rigid
• Pulmonary function
decreases
• Number and size of alveoli
decreases
• Vital capacity declines
• Reduction in respiratory
fluid
• Bony changes in chest
cavity
CARDIOVASCULAR
SYSTEM
• Heart smaller and less elastic
with age
• By age 70 cardiac output
reduced 70%
• Heart valves become
sclerotic
• Heart muscle more irritable
• More arrhythmias
• Arteries more rigid
• Veins dilate
GASTROINTESTINAL
SYSTEM
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Reduced GI secretions
Reduced GI motility
Decreased weight of liver
Reduced regenerative
capacity of liver
• Liver metabolizes less
efficiently
RENAL SYSTEM
• After 40 renal function
decreases
• By 90 lose 50% of function
• Filtration and reabsorption
reduced
• Size and number of nephrons
decrease
• Bladder muscles weaken
• Less able to clear drugs from
system
• Smaller kidneys and bladder
REPRODUCTIVE
SYSTEM
Male:
• Reduced testosterone level
• Testes atrophy and soften
• Decrease in sperm production
• Seminal fluid decreases and
more viscous
• Erections take more time
• Refractory period after
ejaculation may lengthen to
days
REPRODUCTIVE
SYSTEM
Female:
• Declining estrogen and
progesterone levels
• Ovulation ceases
• Introitus constricts and
loses elasticity
• Vagina atrophies - shorter
and drier
• Uterus shrinks
• Breasts pendulous and
lose elasticity
NEUROLOGICAL
SYSTEM
• Neurons of central and peripheral
nervous system degenerate
• Nerve transmission slows
• Hypothalamus less effective in
regulating body temperature
• Reduced REM sleep, decreased deep
sleep
• After 50% lose 1% of neurons each
year
MUSCULOSCELETAL
SYSTEM
• Adipose tissue increases with
age
• Lean body mass decreases
• Bone mineral content
diminished
• Decrease in height from
narrow vertebral spaces
• Less resilient connective tissue
• Synovial fluid more viscous
• May have exaggerated
curvature of spine
IMMUNE SYSTEM
• Decline in immune function
• Trouble differentiating
between self and non-self more auto-immune
problems
• Decreases antibody response
• Fatty marrow replaced red
marrow
• Vitamin B12 absorption
might decrease - decreased
hemoglobin and hematocrit
ENDOCRINE SYSTEM
• Decreased ability to
tolerate stress - best seen
in glucose metabolism
• Estrogen levels decrease
in women
• Other hormonal
decreases include
testosterone, aldosterone,
cortisol, progesterone