Observed Changes in the Musculoskeletal System.....
Muscles
Sarcopenia (↓ muscle mass & contractile force) occurs with age.
Some of this muscle-wasting is due to diminished growth
hormone production, but exactly how much is due to aging
versus disuse is unclear.
Many sources note that muscle is trainable at any age.
Sarcopenia is associated with increased fatigue and risk of
falling (so may compromise ADLs).
Sarcopenia affects all muscles including, for example, the
respiratory muscles (↓ efficiency of breathing) & GI tract
(constipation).
Bone/Tendons/Ligaments
Gradual loss of bone mass (bone resorption > bone 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 seen
in sedentary elders.
Decreased water in the cartilage of the intervertebral discs
results in a ↓ in compressibility and flexibility. This may be one
reason for loss of height.
There is also some decrease in water content of tendons &
ligaments contributing to ↓ mobility.
Observed Changes in the GI Tract
,Some sources claim that one can expect atrophy & decrease in
the number of (especially) anterior (salty/sweet) tastebuds, but
this is controversial.
Basal and maximal stomach acid production diminish sharply in
old age. At the same time, the mucosa thins. Very little seems to
happen to the small bowel.
Decline in number of gastric cells decreased production HCL
(an acidic environment is necessary for the release of vitamin
B12 from food sources).
Decrease in amount of pancreatic enzymes without appreciable
changes in fat, CHO, or protein digestion.
Diminished gastric (eg. pepsinogen) & pancreatic enzymes
result in hinderance to the absorption of nutrients like iron,
calcium, & folic acid.
Hepatic blood flow, size & weight decrease with age. Overall
function, however, is preserved, but may be less efficient in
metabolizing drugs.
Decreased tone in stomach & intestines result in slower
peristalsis constipation.
Observed Neurologic Changes
There is neuronal loss in the brain throughout life (the amount &
location varies). J. Ger. 47: B26, 1992.
Loss is chiefly gray matter not white matter
Slowed neuronal transmission.
Changes in sleep cycle: takes longer to fall asleep, total time
spent sleeping is less than their younger years, awakenings
throughout the night, increase in frequency of daytime naps.
Sense of smell markedly decreases.
,The lens of the eye loses fluid and becomes less flexible, making
it more difficult to focus at the near range.
Dry eyes
Observed Hair Changes
Men:
Men typically lose their hair in the temporal area during their
20s
Hairline recedes and male pattern baldness may occur if the
genetic potential for baldness is present.
Increased hair growth in ears, nostrils, and eyebrows
Loss of body hair
Women
May experience a receding hairline and widening part.
Hair becomes thinner
Increased hair growth about chin & around lips
Loss of body hair
Observed Toenail Changes
Become thicker & more difficult to cut
Grow more slowly
May have a yellowish or opaque color
Recall that these are examples of "normal aging changes" as
opposed to changes related to nail fungus.
Observed Skin Changes -
Epidermis
The number of epidermal cells decreases by 10% per decade,
and they divide more slowly making the skin less able to repair
, itself quickly.
Epidermal cells become thinner making the skin look noticeably
thinner.
Changes in the epidermis allows more fluid to escape via the
skin.
Dermis
These changes cause the skin to wrinkle and sag.
The dermal layer thins
Less collagen is produced
The elastin fibers that provide elasticity wear out.
↓ function of sebaceous and sweat glands contribute to dry skin.
SubQ
The fat cells get smaller
This leads to more noticeable wrinkles and sagging
Endocrine System
Because the endocrine system is so complex and interrelated via
feedback loops, it is difficult to discern the effects of aging on
specific glands.
In most glands there is some atrophy and decreased secretion
with age, but the clinical implications of this are not known.
What may be different is hormonal action.
Age-Related Changes in the Reproductive System
Women
The "climacteric" occurs (defined as the period during with
reproductive capacity decreases (ie, ovarian failure) then finally
stops due to loss of estrogen & progesterone; FSH & LH ↑↑).
This is also described as the transition from perimenopause