Physiology of Aging Flashcards
1
Q
What is aging?
A
- gradual loss in reserve capacity (loss of fxning cells) of organs and organ systems
- leads eventually to fxnl impairment, leading ultimately to death
- gradual process begins in early adulthood
2
Q
What is homeostasis? Effect of aging on homeostasis?
A
- maintains stability of internal enviro
- internal envrio becomes increasingly unstable w/ age
- changes to which the body must respond exceed the body’s diminishing capacity to respond
3
Q
What are reduced homeostatic responses that are common in elderly?
A
- baroreceptor responsiveness: increased postural hypotension
- thermoregulatory responses: higher hypothermia, hyperthermia
- cardiac reserve: fluid overload
- thirst: dehydration
- dark adaptation: night driving hazardous
- skin, mucous membranes: primary barrier - thinner, less blood supply
- mucociliary defenses: cough reflex diminished
- gastric: achlorhydria
- BPH: residual urine
- absence of fever - blunted response
- PMNs altered, t cells altered
4
Q
What are early signs of aging?
A
- process that gradually leads to noticeable changes in many body systems
- MC early sign of aging is difficulty staying up all night and working the next day
- hair thinning in men begins often in 20s
5
Q
SIgns of early aging in 30s?
A
- 30s: easier wt gain graying hair, thinning hair wrinkling forehead and eyes concern about biologic clock, financial security, family obligations injuries "weekend warrior"
6
Q
Signs of early aging in 40s?
A
- reflection on mortality, life’s limitations, unreached dreams and goals - mid-life crisis
- skin changes: sagging, wrinkling, thinning, benign and malignant lesions, sweat glands
- vision changes: presbyopia: MC age related eye problem in this age group, requires reading glasses
- osteoarthritis: by 40 all adults have OA changes visible in radiographs of cervical spine, most of these changes are not sx at this pt - hands, jt, back
7
Q
Signs of aging in 50s and early 60s?
A
- sense of aging
- menopause
- becoming grandparent
- death of parents, friends
- oldest at work
- physical limitations, medical problems
- senior citizen discounts
- AARP membership
8
Q
signs of aging: 70s and 80s?
A
- one or more chronic disabling conditions
- arthritis, HTN, hearing loss, heart conditions, visual problems, bone problems
- psych and social losses:
retirement, death of spouse/close family member
children moving away, freinds dying or moving.
Moving into apt or retirement living.
Inability to socialize from sensory or physical impairments
9
Q
Rule of Thirds: aging changes?
A
- 1/3 fxnl decline is result of disease
- 1/3 is due to inactivity (disuse)
- 1/3 of decline is caused by aging itself
10
Q
What are the theories of aging?
A
- programmed phenomena: all cells bear specific death genes
- error theory: cellular DNA and RNA error, accumulation of inappropriate proteins and enzymes, unable to support cellular metabolism
- repair failure: failure of DNA repair
- redundancy failure: as cell ages, supply of redundant genes are exhausted
- killer hormone theory: pituitary produces “killer” hormone, destroys cell fxn
11
Q
What is the happiest adult age group?
A
- in spite of potentially discouraging losses and limitations they face, men and women aged 65-70 yrs report greater happiness than adults in any younger age group
12
Q
What advantages do older adults have over younger individuals?
A
- greater independence
- fewer responsibilities
- reduces concern about day to day inconveniences
- financial security: social security, retirement programs
13
Q
Multiple etiologies in elderly?
A
- multiple problems are the rule
- illness results from several factors rather than from a single agent
- often several factors combine w/ a decrease in host resistance to illness or injury
14
Q
Aging Changes to hematologic system?
A
- after 65: RBC, Hgb, Hct decrease slightly
- WBCs increase in lobulation and decrease in granulation: impairment of phagocytic activity
- total lymphocyte unchanges, subsets change
- ESR increases slightly
- physiologic anemia of aging
- decreased reserve of red cell mass
15
Q
Aging chages to ht and wt? (musculoskeletal)
A
- ht: avg loss is 2-4 inches (40-80yrs)
- wt:
men - peak in 50s and then decline
women - peak in 60s and then decline
16
Q
Aging changes of the CT? (musculoskeletal)
A
- increase in density, decrease in water content of CT: loss of skin elasticity, jt stiffness (increased fibrous tissue) - TBW men: from 60-54%, women 54-46%
- calcification of CT:
atherosclerotic changes
degenerative jt disease
17
Q
Aging changes of the bone? (musculoskeletal)
A
- decreased bone mineral content causes changes - osteoporosis
age 20: women have greater bone mass
age 50: women=men
age 65: women2x less than men - reduced 35-30% in women
-10-15% men - bone loss in women due to decreased estrogen production - increase in osteoclastic activity, PTH production, decrease in calcitonin
- vit D absorption declines= decrease in calcium absorption
18
Q
Aging changes of the muscle? (musculoskeletal)
A
- decrease in muscle mass due to reduction in number and size of muscle fibers - 30%
- change in muscle strenght begins at age 35
- degree of muscle loss varies - large muscle affected more than smaller muscles
19
Q
Aging changes to the skin?
A
- decreased tone and elasticity
- decline in subq adipose tissue: poor thermal insulation (susceptible to hypothermia)
- yellowing of nails, rigid nails
- hair loss after 30 in men
- decrease in pigment
20
Q
Aging changes to the respiratory system?
A
- physiologic work capacity of 70yo only half that of 20 yo
- decrease in alveolar size - reduces total surface area for gas exchage
- vital capacity decreases progressively 30-70 yrs old (17%)
- elastic recoil decreases due to changes in collagen
- forced residual capacity increases 60% by age 80, changes in chest wall muscles, bone and CT cause decrease in ventilatory fxn
- reduced expiratory flow velocities
- all timed pulm fxns decrease w/ age
21
Q
Aging changes to the CV system?
A
- increased collagen in vascular smooth muscle + decreased elastic tissue: reduced vascular compliance
- CO decreases by 1%/yr b/t 25-70: decreases from 4.6 to 3.3 x resting CO, SV deceases 0.7%/yr
- slight reduction in resting HR
- decreased organ perfusion (increased PVR and decreased CO)
- age 80: blood flow reduced by 50% in kidneys and 20% in cerebral hemisphere
- increased peripheral resistance + decreased vascular compliance = increased systolic BP
22
Q
Aging changes of the Kidneys?
A
- after 40 - decrease in nephron units:
- kidneys begin to lose mass
- renal blood vessels thicken, lose elasticity
- medullary CT increases, replaces interstital cells - decreases in medullary hydration
- loss of juxtamedullary glomeruli - account for decreased renal concentrating ability and decreased renal perfusion
- GFR and CrCl decline after age 40 (1%/yr)
- by 80 - GFR decreased by 50%, and CrCl by 33%
- peak bladder capacity reduced
- residual urine increases
- blood flow best at night, decreased renal perfusion = nocturia nad frequency
- prostate gland doubles in size (20-80 yrs)
23
Q
Aging changes to the alimentary canal?
A
- loss of teeth occurs secondary to bone and CT changes - 1/2 pop over 65 is edentulous
- periodontal disease is more common in middle and old age: decreases ability to chew food adequately
- all contribute to poor nutritonal status
- lack of dental care and poor hygiene contributes
- lower esophageal sphincter fails to relax w/ peristaltic waves = uncoordinated -
delayed entry of food into stomach
decrease in gastric emptying time
GERD
24
Q
Gastric aging changes?
A
- age related changes in stomach lead to atrophic gastritis and pernicious anemia (can present like dementia)
- gastric secretions reduced (achlorhydria)
- unable to absorb B-12
25
Aging changes of the colon?
- decreased motor fxn
- depression of defecation reflex - lead to chronic constipation
- decreased colonic muscle tone - lead to diverticulosis
- decreased perfusion of GI tract secondary to vascular changes - bowel ischemia
26
Aging changes of the pancreas?
- decrease in pancreatic lipase activity = may have effect on digestion
- no alteration in hepatic or biliary fxn, however increaesd incidence of cholelithiasis
27
Aging changes specific to a man?
- increase in fibrous tissue of intertubular spaces of the testes
- thickening of basement membrane around seminiferous tubules = decrease in sperm transport
- sperm production only decreases 50% from ages 20-80
28
Aging changes of the PTH?
- at 20: 2x as high in women as men
- levels decrease in women at 40: rise in middle age, very high in those who develop osteoporosis
- in men, progressively rise until age 60, then decline
29
Aging changes of cerebral blood flow? Neuro changes?
- decrease (20%)
- by 80 - 7% reduction in cerebral hemisphere mass
- NTs esp dopamine in basal ganglia decrease
- delay in monosynaptic reflex arc - slowed reflexes
- motor time increases w/ aging: slowing of activity from reduction in conduction velocity
- decreased vibratory sensation
- decreased hand grip, strength, coordination, writing (micrographia - parkinsons)
30
Aging changes of sleep?
- 90% of adults complain of some problems sleeping
- slowing of alpha rhythm and altered sleep patterns
- more time in bed, less time sleeping
- frequent night time urination
- arthritic pain
31
Memory loss as we age?
- short term is common in elderly and differentiating this "benign forgetfulness" from early dementia is often impossible
- formal mental status eval is indicated if there is concern about cognitive impairment
- worrying about memory loss itself is a sx of normal aging rather than alzheimers, which the sufferer is generally unaware of any mental impairment
32
Ocular changes as we age?
- cataracts (MC cause of blindness in the world)
- macular degeneration
- decrease in visual receptors:
amt of light reaching the retina diminished by 70%, reduced pupillary size, yellowing and clouding of lens
- presbyopia
- decreased number of retinal rods, dark vision
33
Hearing changes as we age?
- decrease w/ age, varies by individual: high pitched sounds
- decrease in vestibular fxn:
loss of hair cells in crista ampullaris, leads to balance problems
34
Change in taste as we age?
- number of tongue papillae and taste buds decrease (70%) - adverse effect on appetite and nutrition
- olfaction declines**
- leads to poor nutrtion
- don't want to eat b/c they can't taste or smell
- leads to wt loss - and can lead to FTT
35
Psychological aspects of aging?
- role changes: retirment
- coping w/ illness
- loss of spouse
- friends dying
- kids are adults and far away or occupied w/ their own family matters
36
Lab value changes as we age?
- ESR increases
- CrCl decreases
- blood glucose rises
- cholesterol rises
- albumin falls
- T3 falls
37
What is healthy aging?
- doesn't imply that there are an absence of limitations
- rather an adaption to changes assoc w/ aging process that is acceptable to the individual
- great variation in responses is seen, the goal is that the older adult lives a personally satisfying and socially satisfactoy life
- healthy aging involves prepartion, adaption, and good fortune
38
What are the 3 factors of healthy aging?
- low probability of disease and disability
- higher cognitive and physical fxning
- an active engagement in life: this concept represents the concept of successful aging most fully, going and doing something meaningful
39
What is the disengagement theory?
- voluntary cutting back on work, social and even family ties
- becomes more satisfied w/ vicarious activities and especially w/ reminiscence
- comes to terms w/ and accepts past failures
40
What is the example of the prototypical disengaged person?
- well known
- loved by neighbors
- happily spends day rocking on front porch, offering cheeful word to everyone who passes by
41
What is the activity theory?
- staying as active as possible
- cont. professional or volunteer work
- social activities, family, hobbies
42
What is the continuity theory?
- successful psych adaption to aging involves allowing personal preferences from earlier yrs to manifest themselves as the individual responds to the stress and challenges of older age
- thus, some individuals will remain more active b/c it suits their personality, whereas others will become more disengaged
