Geriatrics: biological changes of age Flashcards
what is the fastest growing age group?
the “old-old” > 85 years.
what are the demographics of the population 65+ (gender, race, economic status, education)
Mostly female.
Increasing numbers of African Americans and Hispanics.
More affluent, Less dependent on Social Security.
More educated and literate.
geron vs gerontology vs geriatrics
Geron: A Greek word meaning “old man”.
Gerontology: The study of social, physiological, and biological aspects of aging.
Geriatrics: Branch of medicine that studies disease in the elderly.
define “aging”
The process that occurs after maturation.
-A progressive decline in the ability of an organism to adapt to environmental changes.
2 categories of aging processes
- Genetically programmed processes.
2. Accumulation of damage to critical cellular tissue constituents. (genetic theory, damage theory, etc)
what are the 4 changes in body composition with aging?
- decline in lean body mass (sarcopenia)
- increase in body fat
- dec. height (and posture)
- dec. bone mass and density
what is the cause of sarcopenia?
decr. O2 consumption with exercise
what is the cause of incr. body fat?
- Infiltration of fat into muscle causing loss of strength.
- Increases the volume of distribution of lipophilic drugs and prolongs pharmacological action. (ativan, benzos, etc)
what is the cause of decr. bone mass + density?
New bone is not produced by osteoblasts as quickly as old bone is removed (resorbed) by osteoclasts.
3 changes in homeostatic body temp
- Increased loss of subcutaneous fat causes heat loss and HYPOTHERMIA
- Loss of the ability to sweat causes HYPERTHERMIA
- Unable to mount a fever in the face of infection.
incr. of ___ degree(s) over avg. can indicate a fever in the elderly
1 degree
3 changes in HR
- Maximum heart rate is lower.
- Longer amount of time to elevate heart rate.
- Increased recover time after elevated heart rate.
3 changes in homeostatic control: BP
- Impaired baroreceptor.
- Orthostatic hypotension.
- Increased systolic blood pressure with stiffer arteries.
should vital signs be different for elderly?
in general, no but they may have lower HR and higher systolic BP
Resp. rate in elderly. what is the normal range?
Normal can be RR of 16-25.
Maybe more shallow in the elderly.
Anything greater than 25 is concerning for illness. (pneumonia specifically)
why do old people have a lower HR?
Declining β-adrenergic response.
4 part multifactorial cardiac changes in aging ?
- Early diastolic filling is reduced.
- More reliance on atrial contraction to maintain LV filling.
- Needs higher pressures for the same degree of filling.
- High systolic blood pressures.
Older persons may develop signs and symptoms of congestive heart failure with a normal _______ ______. why? what does this mean for txt? (kinda weeds)
Older persons may develop signs and symptoms of congestive heart failure with a normal ejection fraction.
Diastolic dysfunction. so you need GENTLE diuresis
pulmonary changes with aging. (elastic recoil, total lung capacity)
-Elastic recoil decreases = stiffer lungs.
Alveoli collapse sooner with expiration.
-Total lung capacity decreases.
(overall: “we just can’t get the air out”)
pulmonary changes with aging (residual lung vol, FVC and FEV1
-Residual lung volume increases.
Volume of air remaining after normal expiration.
-FVC and FEV1 decreases.
what can result from the PaO2 (arterial O2 tension) decrease with aging? what causes this?
Ventilation/perfusion imbalance from early airway collapse.
- ->Decreased response to hypoxia (low O2) and hypercapnia (high CO2 trapped in lungs).
- caused by: Decreased chemoreceptor function.
anatomic changes in kidney
gets smaller
changes in creatine clearance and renal blood flow
Decreasing creatinine clearance.
Decreasing renal blood flow.
(so Creatinine levels SHOULD be lower - assume theyre kidney fxn isn’t good. if they are normal it may mean that decr. muscle mass and decr. renal fxn are balanced)
why is dehydration is more frequent in elderly?
Renal response to vasopressin decreases causing impaired ability to concentrate urine in a water depravation state.
*decr. sense of thirst
5 GI changes.
what one organ fxn remains unchanged?
Salivary production. Esophageal motility. Gastric acid production. Pancreatic enzyme production. Gastric transit time.
Liver functions remain unchanged.
why are circulating insulin levels unchanged in old people?
A decrease in production is balanced by a decrease in renal clearance.
(insulin resistance is increased)
endocrine changes
decr. hormones levels
neurological changes
cerebral atrophy, slow thought process and memory
-slow rxn time
4 changes of the eye
Cornea flattens and lets in less light.
Loss of lens transparency (cataract).
Reduced elasticity of the lens (presbyopia).
Less efficient retina.
3 results of less efficient retina
Decreased spatial discrimination.
Decreased black and white discrimination.
Decreased adaptation to bright to dark.
what is prebycusis? what does it result in?
Decreased perception of high frequency tones.
Loss of speech discrimination.
sensory changes?
decr. in taste, touch, pain and smell
4 changes in dermatology
- Increased skin fold thickness; Decreased collagen and elastic; Decreased dead cell turn over. (AKA wrinkles)
- Decreased subcutaneous fat layer.
- decr. moisture (less oil production)
- decr. blood supply (fragile blood vessels)
immune changes in elderly, what is the one thing that actually increases?
BUT make more auto-antibodies (have positive ANA and rheumatoid factors but DONT have the disease)
decr. subQ fat later causes what?
Causes loss of heat., Changes in drug absorption
is anemia part of aging?
NO! blood counts remained unchanged
bone marrow changes
marrow mass decr, marrow fat increases
what is frailty?
A gradual loss of functional reserve and increased susceptibility to illness combined with decreased ability to rebound from illness.
what is homeostenosis?
A decreased range of physiological response available to maintain homeostasis. (clinically relevant when syst. is stressed)
why are those at the extremes of age most vulnerable?
they have the least amount of physiologic reserves (babies don’t have any yet, old people have used theirs up)
what is the “hallmark” of frailty?
sarcopenia
define sarcopenia
progressive increase in the discrepancy between the muscle mass and the force it generates.
Hypothesized to be related to increase in fat infiltration into the muscle.
Increased intramuscular fat may have the same metabolic consequences as visceral fat.
