Physiology of Aging

Question 1

Another name for aging is?

Answer 1

senescence

Question 2

Is senescence universal?

Answer 2

no
Prokaryotes do not
only multicellular organisms that undergo somatic cell differentiation

Question 3

Is senescence in humans slowly happening and unavoidable?

Answer 3

yes

Question 4

Rapid senescence?

Answer 4

deterioration after maturation/ reproduction

invertebrates, annual plants, pacific salmon

Question 5

Gradual senescence?

Answer 5

slow but persistance senescence

placental mammmals including humans

Question 6

Negligible senescence?

Answer 6

trees, some reptiles, fish

Question 7

Stochastic (random error) theory?

Answer 7

a potential cause of aging

Accumulation of random damage

Question 8

examples of accumulation of random damage?

Answer 8

somatic mutation such as from ionizing radiation, lack of dna repair mechanisms, cross-linking of intra and extracellular matrix components, glycosylation of proteins resulting in inability to perform primary functions, free radical damage

Question 9

neuroendocrine theory?

Answer 9

holds that degeneration of the hypothalamic-pituitary-endocrine axis is central to aging

Question 10

evidence of neuroendocrine theory?

Answer 10

growth, onsent of puberty, reproduction, menopause, metabolism

Question 11

immunologic theory?

Answer 11

based on observations of decline of immune system with age

Question 12

example of immunologic decline?

Answer 12

decreased t cell response, increased risk of infections, autoimmune responses against self

maybe a secondary aging phenomenon

Question 13

cellular (replicative) senescence?

Answer 13

finite number of replications

noncoding regions of DNA sequences called telomeres which grow shorter on the end of chromosomes with every replication

Question 14

telomerase?

Answer 14

enzyme that can maintain telomere length

Question 15

p53 transcription factor?

Answer 15

blocks proliferation of damaged cells

Question 16

can some tumors/ malignant cells express telomerase?

Answer 16

yes, enabling them to replicate an infinite number of times

Question 17

Presbyopia?

Answer 17

increasing stiffness (loss of accomodation) of the lend of the eye

Question 18

Opacification of the lens

Answer 18

cataracts

results in decreased visual acuity

Question 19

Antioxidant regimen that may be beneficial in preventing and treating ARMD?

Answer 19

500 mg vit C, 400 IU vit E, 15 mg beta carotene, 80 mg zinc as zinc oxide, 2 mg cupric oxide

Question 20

Dry macular degeneration vs wet?

Answer 20

less severe

untreatable

Question 21

prebycusis?

Answer 21

hearing loss of aging
decrease high frequency acuity
results in difficulty hearing to deafness

Question 22

etiology of prebycusis?

Answer 22

loss of cochlea and auditory nerves not in the middle ear

Question 23

4 age changes of cardiovascular system?

Answer 23

decrease arterial compliance
decrease beta andrenergic responsiveness
decrease baroreceptor sensitivity
decrease sinus node automaticity

Question 24

changes in cv system result in?

Answer 24

systolic hypertension
low cardiac output and bp response to stress
impaired bp response to standing and hypovalemia
arrythmias
CHF

Question 25

Describe the aging heart

Answer 25

loss of myocytes fibrosis increases parasympathetic neurons decrase hence use of atropine has less effect on heart effect sclerosis and calcification of heart valves occur

Question 26

Describe vascular aging?

Answer 26

irregularities of size and shape of endothelial cells, fragmentation of elastin in internal elastic and media, increased lumen diameter, vessel length, wall thickness, collagen increases, cross linking (esp in subendothelium), decreased basal and stim NO production, increase in systolic and pulse pressure, independent of cholesterol, non-inflammatory, uniform in all large arteries

Question 27

Most common valve problem?

Answer 27

stenotic aortic valve

Question 28

Aging impact on Lung function?

Answer 28

lower maximal expiratory flows lower diffusing capacity lower P02 and Sp02 as a consequnce of V/Q mismatch lower respiratory muscle strength and endurance stiffer chest wall increase lung tissue compliance (less recoil) reduced respiratory drive

Question 29

5 things with aging respiratory system?

Answer 29

``` decrease lung elasticity decrease rate of diffusion increase chest wall stiffness decrease cough reflex results in: decrease resting p02, increased risk of aspiration and infection ```

Question 30

Aging Respiratory impact on individual?

Answer 30

less exercise capacity higher susceptibility to pulmonary disease higher incidence of respiratory tract infections use of cough reflex to clear secretions due to decrease ciliary action

Question 31

Tooth loss?

Answer 31

dependent on disease (periodontal infections and carries) rather than pure aging process

Question 32

Aging GI system?

Answer 32

``` decreased hepatic function decreased gastric acidity decreased colonic mobility decreased sensitivity of taste buds Results in: delayed metabolism of some drugs, constipation, poor appetitie- malnutrition ```

Question 33

Taste and eating habits are good indicators of?

Answer 33

aging vs medically compromise

Question 34

Most changes of function/ structure of upper GI tract in elderly are result of?

Answer 34

path changes secondary to disease not aging alone

Question 35

Physiology that does not change with age?

Answer 35

esophageal function persists until very advanced age incidence of reflux is stable but the duration of each reflux episode is longer gastric emptying of solids remains stable although liquid emptying is prolonged small bowel transit times remain stable

Question 36

Aging renal system?

Answer 36

decrease GFR (10 percent per decade after 50) results in: delayed clearance of some drugs decrease in urine concetration/ dilution ability

Question 37

Kidney mass peak?

Answer 37

4th decade | `

Question 38

decline in renal function accompanied by?

Answer 38

thickening of basement membrane messangial expansion focal glomerulosclerosis

Question 39

Skin changes in aging?

Answer 39

``` thinning of epidemis and dermis atrophy of subcutaneous adipose tissue decreased vascularity decreased oil and sweat production results in: bruising, skin tears, pressure sores ```

Question 40

Skin lesions?

Answer 40

not normal aging

Question 41

Eczema?

Answer 41

common

Question 42

Aging MSK system?

Answer 42

``` decrease muscle mass decrease bone density results in: decrease strength and endurance osteopenia/ osteoporosis ```

Question 43

skeletal scenscence?

Answer 43

decrease bone mass decrease bone strength increase risk of fractures

Question 44

skeletal m aging results in?

Answer 44

limited ability to climb stairs, rise from chair increase risk of falling contributes to heat and cold intolerance

Question 45

rate of decline in skeletal m? (weak vs conditioned)

Answer 45

similar in both, exercise however will produce increased short term endurance

Question 46

Aging cartilage?

Answer 46

decrease cartilage hydration smaller proteoglycans, same number, increase cross linking reduced proliferation of chondrocytes and reduced metabolic activity

Question 47

Aging brain/ nervous system?

Answer 47

``` decrease brain size (atrophy) decrease NT, catechol and dopamine decrease righting reflex decrease stage 4 sleep impaired thermal regulation results in: slower speed of memory and calculation stiffer gait increased body sway insomnia lower body temp at rest ```

Question 48

Nervous system aging

Answer 48

``` decreased brain weight decreased cortical cell count neuronal loss decline NT productions loss of synaptic receptors decline cerebral metabolism decline # of mitochondria have been observed in aging synaptic cells ```

Question 49

Central, Motor, and Sensory NS

Answer 49

``` increase motor response time slower pyschomotor performance decrease intellectual performance decrease complex learning decreased hour of REM and total sleep ```