physiology of ageing Flashcards
- nutrition
•Protein, vitamin & mineral requirements remain the same, but
kilojoules requirements lessen.
•Decreased renal function increased risk of dehydration & renal
calculi
•Loss of calcium & nitrogen (in non-ambulant persons)
•Decreased enzyme activity & gastric secretions
•Reduced pepsin & hydrochloric acid secretion
decreases
absorption of calcium & Vitamins B1 & B2 , C & K
•Decreased salivary flow & sense of taste reduced appetite &
increases intake of sweets & spicy foods
•Decreased intestinal motility & peristalsis of large intestine.
•Thinning of tooth enamel brittle teeth
•Decreased biting force
•Diminished gag reflex
- (integumentary system
- skin
- nails/hair
SKIN
The skin loses underlying subcutaneous fat & oil
glands, causing wrinkles and reduced elasticity.
•Loss of collagen & elastin decreased rate of
skin replacement. Woman’s skin show signs of
ageing about 10 years earlier than men because
it’s thinner & drier
HAIR
•Pigmentation decreases hair turns white or grey
•Hair thins as melanocytes declines by age of 70, hair is baby fine
again, balding may occur
•Hormonal changes cause pubic hair loss
•Facial hair may increase in post menopausal women & decrease in
men
NAILS •The nails become thicker due to reduced blood flow to the connective tissues. •They grow at different rates •Thickening of nails & longitudinal ridges, flaking, brittleness & malformations may increase •Toenails may discolour
- vision
•Starting in the 40’s, the pupil begins to decrease in size & in
response time to light.
•The pupil becomes smaller & the person requires three times the
amount of illumination as a younger person to see.
•Focusing takes longer with an increase in nearsightedness, making
small print harder to read.
- Night vision decreases & depth of
perception
•The eyes sit deeper in their sockets &
eyelids lose elasticity baggy & wrinkled
•Lacrimal apparatus loses fatty tissue
decreases quantity of tears & evaporation
occurs more rapidly
•The cornea loses it’s lustre & flattens
•The iris fades or develops irregular pigmentation
•The vitreous can degenerate opacities & floating vitreous debris
& can also detach from the retina
•The lens enlarges & loses transparency
•As cones deteriorate impaired colour vision especially in the blue
& green ranges
Cataracts
•A gradual yellowing of the lens resulting in loss of
transparency
•Cataract surgery is an outpatient procedure with a
very high success rate.
•Due to the lack of modern medical technology in
the developing world, it is also the world’s leading
cause of blindness.
Aged-related macular degeneration
•Is a degenerative disease of the macula.
•There is no way yet of repairing the vision
that has been lost, but if detected early laser
surgery can help slow the progression of the
disease.
•(AMD) is the leading cause of vision loss in
people over age 65.
Glaucoma
•The fluid pressure inside the eye increases,
leading to loss of side vision and eventually total
blindness.
•The increased pressure destroys the optic
nerve.
•With early detection, it can be kept under
control with pressure reducing eye drops and
surgery.
•Chances of developing it increase with age.
Diabetic retinopathy
•This complication of diabetes is a leading cause of
blindness
•The longer a person has had diabetes the more apt
they are to develop diabetic retinopathy.
•Laser surgery can slow the progression of this
disease along with management of blood glucose
levels.
- hearing
•Hearing loss usually starts in middle age & worsens with age, affects
males more than females
•Slowly progressing deafness of ageing is called presbycusis or senile
deafness
•Decrease in sensitivity to high frequency tones & discrimination of
similar pitches, usually as a result to normal changes to the bones &
cochlear hair cells of the inner ear & changes to the peripheral &/or
central nervous system.
•Age related hearing loss is irreversible
- respiratory
•Nose continues to grow (due to ongoing cartilage growth)
•Atrophy of the tonsils & tracheal deviations occur from changes in
the ageing spine
•Airways & lung tissue become less elastic with reduced cilia activity, decreased oxygen uptake & exchange.
•Oxygen saturation decreases by 5%
•Lungs become more rigid & the size & number of alveoli decline
•A 30% reduction in respiratory fluids increase the risk of pulmonary
infections & mucous plugs
•Rib cage muscles also atrophy, further reducing the ability to
breathe deeply, cough & expel carbon dioxide.
• Lack of oxygen can also increase anxiety
6.gastrointestinal
•Decreased mucosal elasticity & G.I secretions modifications to digestion & absorption •G.I tract motility, abdominal wall, bowel wall & anal sphincter strength may decrease. •Changes in the liver include: • decreased weight • reduced regenerative capacity • decreased blood flow • less effective in metabolising drugs & detoxifying
- cardiovascular
•Heart usually becomes smaller & loses it’s
contractile strength & efficiency
•By age 70 cardiac output at rest is reduced
by 30%-35% in many individuals
•Fibrotic & sclerotic changes atrophy the heart muscle, especially
the left ventricle
•Thickness of left ventricle increases by 25% between ages of 30 - 80
• Calcification of the heart valves
• Loss of elasticity in artery walls (arteriosclerosis)
• Intra-arterial deposits (atherosclerosis)
•Myocardium becomes more irritable, extra systoles may occur
along with sinus arrhythmias & sinus bradycardias
•The veins dilate & stretch decreasing coronary artery flow by
35% between the ages of 20 and 60
•The aorta becomes more rigid systolic BP to rise
disproportionately higher than diastolic resulting in a widened pulse
pressure
•ECG changes include increased PR, QRS & QT intervals & decreased
amplitude of the QRS complex & a shift of the QRS complex to the
left
•Response to physical & emotional stress may decrease
•Heart rate takes longer to return to normal after exercise
•Decreased strength & elasticity of blood vessels venous &
arterial insufficiency
- renal
After 40, renal function may diminish, by 90 this could be as high as
50%, this is reflected in a decrease in the glomerular filtration rate.
•Renal blood flow decreases 53% from reduced cardiac output &
atherosclerotic changes
•Impaired clearance of drugs
Size & number of functioning nephrons decrease decline in
tubular reabsorption & renal concentration ability
•Size of kidneys & bladder decreases
•Bladder muscles weaken incomplete emptying, chronic urinary
retention & nocturia
•By age 70 blood urea nitrogen levels rise by 21
- reproductive
Male •Reduced testosterone testes atrophy & soften •May lose libido •Prostate gland enlarges
Female
•Reduction of oestrogen emotional & physical changes
•Menopause occurs about age 50
-ovaries & vulva atrophies
-vagina atrophies shortens & mucous lining thins, dries & is less elastic.
• pH becomes more alkaline & normal flora changes increased risk of infections
•Uterus
•shrinks rapidly
•Cervix atrophies loss of mucous production
•Endometrium & myometrium become thinner
•Breasts
•Glandular, supporting & fatty tissues atrophy
•Cooper’s ligaments lose their elasticity pendulous
breasts
Pelvic supports relax, starts during labour & delivery progresses
rapidly with depletion of oestrogen at menopause
Signs & symptoms include: -
pulling around inguinal ligaments
lower back pain
pelvic heaviness
urinary stress incontinence.
- neurological
•After age 25, everyone starts to lose nerve cells.
•With age the brain shrinks in size
•Neurons of the central & peripheral nervous system degenerate
•After 50 brains cells decrease at a rate of approx 1% a year (not
noticed until age well advanced)
•Hypothalamus is less effective
•Cerebral cortex loses 20% of neurons
•Corneal reflex slows
•Pain threshold increases
•Decrease in stage 3 & 4 sleep
frequent waking.
- MUSCULOSKELETAL
•Reduction in lean body mass muscle weakness
•Increase of adipose tissue stores
•Decrease in height (due to spinal curvature & narrowing of
intervertebral spaces)
•Bone mineral reduction
•Reduction of resilience & elasticity in joint & supporting
structures
•Synovial fluid more viscous
•Difficulty in tandem walking walks with shorter steps & a
wider stance for balance & stable weight distribution
