Physiology II: Physical Changes with Ageing

Physical condition is less determined by age and more driven by: … (3)

lifestyle choices, genetics, environment

Cells of the elderly (regardless of when they last underwent …) look the same as younger cells, however they do not withstand a variety of challenges

mitosis

Theories of aging: … (6)

programmed ageing theory, somatic mutation theory, wear and tear theory, cross-linking theory, free radical theory, immunological theory

Programmed aging theory: … (2)

Hayflick phenomenon, telomere shortening

Usual to successful aging for clinicians: … (5)

exposure, psychological well-being, cognition, nutrition, exercise

Deposits of … accumulate in the heart

lipofuscin (ageing pigment)

Valves of the heart … and become stiffer

thicken

The number of … decreases and fatty & fibrous tissues increase about the SA node. these changes may result in a slightly slower heart rate

pacemaker cells

The heart walls thicken and the … that the chamber can hold decreases

amount of blood

Heart fills more slowly and the … to filling doubles (in precentage)

atrial contribution

An ageing heart is slightly less able to …

tolerate increased workloads

with aging and coronary artery disease the … is lowered

ejection fraction

With ageing arteries thicken and stiffen in the … and … of large arteries

media, intima

large arteries thicken and stiffen due to: … (4)

collagen deposition, cross-linking, fragmentation of elastin, calcium deposition

With ageing smaller arteries may thicken and stiffen and theri ability to … diminishes significantly

dilate and constrict

Age-relates changes to … are minimal and do not impede normal functioning

veins

The aorta becomes thicker, stiffer and less flexible. this makes the … resulting in LV hypertrophy

blood pressure higher (increased afterload)

Increased large artery stiffness causes a fall in …, associated with a continual rise in … (if left untreated will increase artery stiffness)

diastolic blood pressure, systolic blood pressure

… become less sensitive with ageing, this contributes to the relatively common finding of orthostatic hypotension

baroreceptors

a … is observes with ageing, and therefore blood volume decreases

decrease in total body water

The number of red blood cells (… and …) are reduced, but not significantly, the white blood cells stay the same but … decrease in number and effectiveness

hemoglobin, hematocrit, lymphocytes

the … of bone marrow decreases moderately

cellularity

… of the immune system become less effective

nonspecific defenses

the ability of the body to make … diminishes

antibodies

… and increased in older adults, increased frequency of +ve RhF, ANA, and false positive syphilis screens in healthy older adults

autoimmune

the … (which produced hormones that activate the T cells) atrophies throughout life

thymus gland

The peripheral blood T-cells … in old age

proliferate much less

Common infections are often more severe with … and decreased chances of developing …

slower recovery, adequate immunity

The number … in the lungs and their level of activity is reduced

cilia

… in large airways are reduced

glandular cells

decreased number of … in larynx

nerve endings

… is blunted thus decreasing the effectiveness of cough

cough reflex

Decreased levels of … in nose and lungs → decreased ability to neutralize viruses

secretory IgA

Thw number of … do not chnage sigificantly in the lungs

alveoli

The number of … decreases as the alveolar walls become thin, the alveoli enlarge, are less elastic

functional alveoli

Decreased elasticity of the lungs may be due to …

collagen cross-linking

The loss of elasticity accounts for …; unlike in smokers there is little to no destruction of the alveoli

senile hyperinflation

The … drops by 30 mL/year during adult life

FEV1

… is diminished by about 20%

VC

… increases by about 50%

RV

Combine less functional alveoli with slightly thickened capillaries → decreased surface are available for …, less O2 to supply vital organs, especially in setting of acute respiratory illness

O2-CO2 exchange

The respiratory muscles lose .. and …

strength, endurance

There is … in the chest wall

decreases compliance

Pulmonary vasculature becomes less elastic, pulmonary artery thickens and enlarges, increases resistance to blood flow in lungs, increases …

pulmonary artery pressure

… become smaller and thicker reducing renal blood flow

renal blood vessels

Decreased renal blood flow from about … at age 40 to … at age 80

600 mL/min, 300 mL/min

Kidney size decreases by … by age 90%, this loss occurs primarily in the cortex where the glomeruli are located

20-30%

Decreased GFR, typically begins to decline at about age 40, by age 75 GFR may be about … than young adult

50% less

There is a decline in the number of …, an increase in tubular diverticula, thickening of the tubular walls → decreased ability to concentrate urine and clear drugs from the body

renal tubular

Overall kidney function, however, remains normal unless there is … on the system

excessive stress

The muscular ureters, urethra, and bladder lose .. and …

tone, elasticity

… with age in the bladder

residual volume

Decline in bladder capaciy from about 500-600 mL to about … → less urine can be stores in the bladder

250 mL

… occurs with ages, some of this muscle wasting is due to diminished growth hormone production but exactly how much is due to aging versus disuse is unclear

sarcopenia

Sarcopenia is associated with … and …

increased fatigue, risk of falling

gradual loss of bone mass (… > …) starting around age 30

bone resorption, bone formation

Decreased water content in …

cartilage

There is also some decrease in water content of … contributing to decreased mobility

tendons and ligaments

In the GI system there is a decrease: … (6)

absorptive cells, motility, sphincter activity, blood flow, gastric acid secretion, active transport

Atrophy and decrease in number of …

anterior tastebuds

Decrease in … and gastric mucosa thins

stomach acid production

decrease in number of gasric cells → decreased production … → decreased … → … absprption

HCL, IF, vitamin B12

… but no significant decrease in fat, carb and protein digestion

pancreatic enzymes

Decrease in gastric and pancreatic enzymes → impaired absorption of … (3)

Fe, Ca, Folic acid

Hepatic blood flow, size and weight is decreased, function is preserved but there is a decrease in …

drug metabolism

Loss is chiefly … in the brain

gray matter not white matter

There is some evidence that although some neuronal loss occurs with age, many neurons have increased … which may (at least partially) compensate for neuronal loss in some areas of the brain

dendrite growth

neuronal transmisiion is …

slowed

It takes longer to …, total time spent sleeping is less than in younger years, awakenings throughout the night, increase in frequency of daytime naps

fall asleep

…arophy, and there is a general decrease in nerve cell number

basal ganglia

decrease in … and increase in mucle …, decrease in step height, and increase in reaction time

dopamine, rigidity

In the PNS there is decreased …

vibration sensation

…: high frequency hearing loss

Presbycusis

… leading to dizziness

vestibular dysfnction

Age-associated factors in special senses: … (6)

presbycusis, vestibular dysfunction, small, teeth, taste, salivary function

Age-associated factors in vision: … (6)

visual acuity, dark adaptation, peripheral vision, contrast sensitivity, accommodation, dry eyes

Men lose hair hair about their temples during their 20s, hairline recedes or male pattern baldness may occur, increased hair growth in … (3), loss of body hair

ears, nostrils, eyebrows

Women usually do not bald but may experience …, hair becomes thinner, increased hair growth about chin and around lips, loss of body ahir

receding hairline

Toenails: … (4)

thicken, difficult to cut, grow slowly, yellow

The number of … and they divide more slowly making the skin less able to repair iteslf quickly

epidermal cells decreases by10% per decade

Epidermal cells become thinner making the …, and allows form more fluid to escape the skin

skin look thin

the … flatten out

dermal-epidermal junction

These changes cause the skin to wrinkle and sag: … (3)

dermal layer thins, less collagen produced, elastin fibers provide elasticity wear out

…: rough, leathery looking skin with wrinkles, irregular pigmentation, plaques, broken blood vessels and actinic keratosis

Solar elastosis

Most endocrine glands there is … with age, but the clinical implications of this are not known

some atrophy

Most apparent changes in hormonal alterations: … (3)

glucose homeostasis, reproductive function, calcium metabolism

More subtle changes in hormonal alterations: … (2)

adrenal function, thyroid function

…: ovarian failure loss of estrogen and progesterone; FSH and LH increase

Climacteric

Physical changes in women: … (7)

hot flashes, irritability, depression, headaches, myalgias, sexual desire (variable)

Women may experience atrophy vaginal issues due to …: thinning and dryness; agglutination of labia majora and minora

low estrogen levels

Men …, testes become softer and smaller, erections are less firm, fewer viable sperm are produced, less seminal fluis may be ejaculated, may not experience oragasms

testosterone declines