Normal Aging Flashcards
Identify problems with the connotation of “normal aging”
when things that are “common” considered “normal”, they are traditionally no longer treated. The example was memory loss- there should not be memory loss with age and if there is, it can not be considered normal. The analogy is blood pressure. It should not just rise because it is possible to keep it down and even lowering a portion of what it is can do a great deal to prevent stroke, heart atack etc
Describe methodological challenges in studying aging physiology, particularly as applied to the nervous system: Longitudinal studies:
What are cohort effects?
are rare
Dropouts — why did they drop out?
How do we separate (subclinical) disease from aging changes?
Heterogeneity — generalizations more difficult; if something happens to an entire generation, does that mean that that’s an effect of age, or just of that generation (great depression, war, etc)
Give examples of physiologic heterogeneity as it relates to changes in the nervous system in older adults
excess capacity in organs and biological systems; we’re given this reserve at birth, and it tends to decrease over time.
The degree to which this is true is HETEROGENEOUS – note the clustering at 40 c/w the spread at 100
even when most of the excess capacity is gone, we may experience little or no decline in function.
A secret of successful aging is to slow down the loss of physiologic reserve.
Describe changes in physiology and anatomy affecting the nervous system with age
Significant molecular, structural, cytoskeletal, neurochemical and vascular changes in the brain.
Structural changes are diffuse – affect cerebellum as well as cerebrum
Gray matter = linear decline; white matter = nonlinear decline.
Increase in atherosclerosis and arteriosclerosisRecall physiologic reserve
motor changes:
Possible contribution of motor unit “dropout” to age-related sarcopenia Decreased strength Decreased speed of gait Stretch reflexes less sensitive Ankle reflexes may be decreased Decreased “righting” reflexes
while bp has been shown to increase almost universally as people age, this can not be thoguht of as normal because:
even lowering bp by a fraction can prevent stroke and other major disabiling events
Disease is common but
disease is never normal.
Use of normal implies not beneficial to treat
Stenosis refers to the narrowing of a structure. In this case, it is used to signify an encroachment on function, illustrated above by the progressively smaller area under the “physiologic limit” curve, with increasing age. When the body is subjected to stress, it uses _______ to ______. The _______. With age, the physiologic reserves of each organ system diminish. As a result, an insult, easily buffered by the young organ, may push the older organ’s ability to maintain homeostasis beyond the “physiologic limit,” leading to an acute injury or disease state.
An example is the aging heart. Exercise increases the oxygen demand of the body. Functional reserve allows the heart to respond by increasing cardiac output (CO) accordingly. In the older heart, loss of cardiac functional reserve limits the extent to which the heart can augment CO in response to exertion. This can predispose the heart and other organ systems to disease as a result of an inadequate blood supply.
Note the decline in physiologic reserve on the right side of the picture. This illustrates the drop-off in reserves that occur in the very end stages of life.
This is one explanation for why it is common for very elderly individuals to be “frail”, susceptible to more disease and injury, and less able to recover from such states.
physiologic reserves, maintain homeostasis, greater the stress, the more physiologic reserves are engaged.
Structural changes are diffuse – affect:
cerebellum as well as cerebrum
Gray matter displays a=______; white matter = _______.
linear, nonlinear; Increase in atherosclerosis and arteriosclerosisRecall physiologic reserve
what is responsible for volume loss?
Nerve cell death; dendritic retraction and expansion; synaptic loss and remodeling; glial cell reactivity
the two pathological factors that may be involved in degeneration at the molecular level of the cytoskeleton:
amyloid plaques, and tau/alpha-synuclein proteins: insoluble depositions in the extra cellular space
the presence of amyloid plaques, and tau/alpha-synuclein proteins:
IS PRESENT IN NORMALLY AGING ADULTS AND DOES NOT CERTIFY THAT THE PERSON HAS AD
TESET: amyloid plaques, and tau/alpha-synuclein protein deposits are _______ while the difference is that the plaques and tangles are ______ in AD as compared to normally aging adults
present in both normally aging adults and patients with AD; more focused in the medial-temporal region as opposed to normally aging adults (all dependent on location and amount of accumulation)
some of the pathologic neuronal changes include:
Dendrites regress and there is loss of dendritic branches and spines – affects neuroplasticity and ability to handle insults (reduces physiologic reserve); results in a loss of synapses; also may reflect failure of cells to eliminate products of peroxidation-induced cell damage
if someone comes in complaining of dry mouth, constipation, uti, delerium, it could be due to:
using an anti-cholinergic because older adults already have a decrease in cholinergic transimission, and any additional hit to their cholinergic level can cause drastic side effects; also a factor with a decrease in dopaminergic transmission
also possilbe causes of decreased function could be due to:
Cerebral Metabolism
Mild reduction in glucose use
Animal studies show vulnerability to metabolic stresses
Mitochondrial Function
Decrease in numbers, increase in size
Dysfunction linked to several neurodegenerative disorders
in the peripheral nervous system, you have ______ which presents as a decrease in reaction time
Motor: Innervation of skeletal muscle decreases
Slowing of nerve conduction
the _______ test is sometimes used to measure cognitive processing speed and _______
digit symbol substitution; working memory
there has shown to be some decline in _______ but these changes are :
vocabulary (synonym and antonym) but these are much less significant than cognitive effects associated with age-related medical conditions and neurodegenerative disease
the _______ test is sometimes used to measure cognitive processing speed and _______
digit symbol substitution; working memory
there has shown to be some decline in _______ but these changes are :
vocabulary (synonym and antonym) but these are much less significant than cognitive effects associated with age-related medical conditions and neurodegenerative disease
age related changes do not impact upon:
job performance, everyday function, or ability for one to do their normal daily activities
ones ability to perservere through normal aging depends on:
what their reserve is, what their baseline functioning is, and what coping mechanisms they come up with for things like not multi-tasking, doing single tasks
TEST: the reason we see the most decline in ______ on tests like _______ is because of declines in _______, this means declines in attention and cognitive processing speed (the greatest) reaction time longer, working memory, visuospatial orientation
working memory, digit symbol substitution test, “fluid intelligence”, especially attention and cognitive processing speed
TEST: As we age______ declines, which means there are declines in things like:
_______ ;
__________ remains stable or is improved, which includes factors like:
“fluid intelligence” Attention and cognitive processing speed (greatest) Reaction time longer “Working memory” Visuospatial orientation;
Crystallized intelligence, vocabulary, judgement
sensory changes:
Decreased proprioception Position sense Decreased vibratory sense proprioception Eventually leads to decreaase in ability to right oneself, and resulting in more falls
Studies on exercise and aging:
LIFE MIND did not demonstrate a difference between the groups after 24 months of physical activity (?contamination effect?)
Other studies have shown decreased agitation and better sleep in dementia
decreased progression from MCI to dementia
Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulin like growth factor I and had a favorable effect only on Trails B performance.
TEST: ______ is the cognitive function that is most affected by age
working memory, processing speed, reaction time, attention: “short term recall should always raise red flags”
TEST: the anual strikeout rate increases annually for hitters after the age of 30?
yes bc their reaction time has slowed/decreased
TEST: as we grow older:
crystallized intelligence/ wisdowm /judgement/ vocabulary remains stable or may increase with age- the “wisdom” concept: it is fixed and does not decline (may be protective/increased-cross connections)
