Nervous System - Notes (Changes and
Suggestions in blue and green - 3/6/06)
1.
Name and explain the importance of the six ways that the nervous
system contributes to homeostasis and quality of life.
- monitoring - detect changes, obtain
information, pleasure
- communicating - informing parts of
situations
- stimulating - controlling actions
- coordinating - promote cooperation, reduce
antagonism
- remembering - faster and more accurate responses in
the same situation
- thinking - faster and more accurate responses in
different situations, problem-solving, creativity, variability in responses,
ethics, politics, etc.
2.
Name and briefly explain the purposes of the three main
functions of neurons (i.e., reception, conduction, transmission). (p. 119)
- reception = picking up information about changes =
detecting stimuli
- conduction = carrying information to another
location in the body using action potentials
- transmission = passing information or signal or
stimulus or inhibitory message to another cell (neuron, muscle, gland)
- uses synapses, neuromuscular
junctions, neuroglandular junctions
- note different transmitter
substances
- note one-way conduction,
modulation, convergence, divergence, memory
3.
Briefly describe the purposes (not the parts) of sensory neurons,
somatic motor neurons, autonomic motor neurons, reflexes, conscious sensation,
and voluntary motor pathways. (pp. 122-124)
- sensory neurons - to detect and communicate about
conditions
- somatic motor neurons - control skeletal muscles
(reflex and voluntary motions)
- autonomic motor neurons - control involuntary
muscles and glands
- reflexes - negative (or sometimes positive)
feedback loops for fast, accurate, predictable responses
- conscious sensation - for conscious remembering,
thinking, pleasure, learning, communication
- voluntary motor pathways - for voluntary movements
4.
Name two age changes in the functioning (not structure) of
skin receptors and skin sensory neurons and describe how they affect the
nervous system's abilities to contribute to homeostasis and quality of life.
(p. 51)
- ¯ sensitivity to touch and pressure
- ¯ localization
- ¯ two-point
discrimination
- ¯ ability
to identify objects by touch
- ¯ speed
of response to touch -> ¯ sensation
of vibration
- these age changes in functioning result in;
- ¯ negative feedback regulation
- ¯ precise control of voluntary
movements
- ¯ pleasure
- affect social, psychological,
economic realms
5.
Name and describe two effects of aging on the ability to smell,
and describe two outcomes from these age changes.
- effects; (1) ¯ detection of aromas and (2) ¯ identification of aromas
- outcomes; altered eating, ¯ detection of "toxins", ¯ detection of undesirable aromas
(embarrassment)
6.
Describe the overall effects of aging on taste sensations.
- very
variable decline in detection of salt but thresholds remain so
low that there is little, if any, practical effect (except with diet {salt}
restrictions)
7.
Name two age changes in sensory function other than changes in skin
sensations, sense of smell, or sense of taste, and describe an outcome from
each age change you select.
- ¯ detection
of (1)
BP, (2) thirst, (3) bladder fullness, (4) bowel fullness, (5) proprioceptors
-> (1) BP, (2) dehydration, (3 & 4)
incontinence, (5) ¯ muscle
coordination
8.
Describe two functional (not structural) outcomes in muscles from
age changes in somatic motor neurons, and give an example of how these outcomes
might affect a person's homeostasis or quality of life.
- ¯ #
motor neurons, variability in speed of APs in motor
neurons, slower neuromuscular junctions
- outcomes: ¯ precision of control (fewer but
stronger motor units), ¯ peak
strength, ¯ speed to achieve peak strength,
prolonged contraction (delayed relaxation) -> difficulty with very fast movements
(e.g., sports, games, jobs)
9.
Choose two age changes in autonomic motor functions and briefly
describe their effects on homeostasis or quality of life.
- ¯ BP
reflex to maintain BP -> orthostatic hypotension -> dizziness, fainting,
falls
- ¯ BP
reflexes (¯ parasympathetic heart inhibition, ¯ adjustments of heart to inspiration
and expiration, ¯ adjustments when exercise ends) ->
BP
- ¯ regulation
of vessels in skin - ¯ temp.
regulation
- ¯ parasympathetic
reflex control of vessels for erection -> slower and reduced erection
- ¯ pupillary
reflexes (photopupil and ciliospinal)
- ¯ # of
neurons in esophagus (Auerbach's plexus) -> slower, weaker, less
coordinated, less complete swallowing
- ¯ sensitivity
to norepinephrine (heart {¯ c-AMP}, lungs {¯ receptor affinity}, other organs {¯ # of receptors}) -> blood norepinephrine (partial
compensation)
10. Describe the overall effects
of age changes in autonomic motor functioning.
- little if any overall effects in most autonomic functions
(unless body is put in extreme conditions; then note exception in previous
objective)
11. Describe the basic operation and overall
purposes of reflexes. (p. 122)
- sensory neurons -> CNS synapses and neurons -> motor
neuron -> response
- usually negative feedback mechanisms -> homeostasis
- occasionally positive feedback (e.g., erection)
12. Name four age changes in the
functioning of reflexes, describe the effects of these changes on homeostasis
and quality of life, and list four specific reflexes that show normal
age changes.
- (1) need stronger stimulus to initiate reflex (¯ # and ¯ sensitivity of receptors)
- (2) slower response (slower reception and weaker and
slower APs)
- (3) weaker and prolonged responses (¯ # motor neurons, less synchronous
motor APs, less effective neuromuscular junctions)
- (4) great ¯ in
coordination in complex reflexes (e.g., balance) (result largely from CNS
changes)
- also affected by (1) stiffer tissues, which ¯ receptor sensitivity, (2) weaker
muscle and gland functioning
- overall ¯ negative
feedback responses -> ¯ homeostasis
- (e.g., swallow, gag, cough,
balance, sweating, withdrawal reflexes)
- overall ¯ positive
feedback responses - ¯ pleasure
(erection)
- partial compensation by altered/improved strategies to
decrease need for fast strong reflexes (e.g., change in gait)
13. Describe three overall results of
nervous system aging on conscious sensation, and explain the effects
from these changes on homeostasis and quality of life. (p. 123)
- ¯ detection
of stimulus
- ¯ identification
of stimulus
- ¯ evaluation
of strength of stimulus
- effects = ¯ learning, ¯ pleasure, ¯ control of movement
- compensation by strengthening stimulus, allowing more time
14. Describe the overall effects
of nervous system aging on voluntary movement, and explain the effects
from these changes on homeostasis and quality of life. (p. 124)
- weaker
- slower
- prolonged movement
- less accurate movement
- less coordinated movement
- effects diminish all strength, fast, and skilled
activities
- compensation by choosing other activities, use of more
efficient motion strategies, "youth vs. experience", use of
assistance devices (e.g., canes)
15. Describe the age changes in the
numbers of CNS neurons and CNS synapses, the overall effects from these
changes, and the reasons for these effects. (p. 131)
- ¯ neurons
and synapse numbers in different regions
- ¯ neuron
and synapse numbers seem to have little effect
- ¯ neurons
and synapse numbers may have beneficial effects
- overall effects = small effects because of (1) neuron
plasticity, (2) loss of "reserve" neurons and synapses, (3) loss of
"error" neurons and synapses
16. Describe or define the meaning of
the following aspects of mental activity. (pp. 132-135)
- short-term memory (1)
-
long term memory (1)
- incidental memory
(1)
- procedural memory
(1)
-
explicit memory (1)
-
implicit memory (1)
-
episodic memory (1)
-
working memory (1)
-
thinking (1)
-
crystallized intelligence (1)
-
fluid intelligence (1)
-
personality (1)
17. Describe the effects of aging on three
different types or aspects of memory or thinking (any combination of three
changes), personality, and one change in sleep. Types of memory include short
term, long term, incidental, procedural, explicit, implicit, episodic, working.
Types of thinking (intelligence) include crystallized intelligence and fluid
intelligence.
- all show
very variable changes between individuals and at different ages for each
individuals
- short
term memory - very variable among individuals but slight average
decline(difficult to detect), especially after age 60-70, and especially for
quick, verbal, unfamiliar, irrelevant information
- recall improved by slow
presentation, association, organization, relevance, reference to concrete
concepts, mnemonic, more time to respond, relaxed atmosphere for response
- long term memory - usually no
significant change
- incidental memory - usually little
change except under time constraints
- procedural memory - usually little
change except under time constraints
- explicit memory - usually
decreases, especially with short time constraints
- implicit memory - usually little
change, but declines when attempting to consciously remember specific
information
- episodic memory - usually
decreases, resulting in confusing times and places of passed
events
- working memory - usually decreases,
resulting in decreases in complex mental processes
- thinking - very variable
among individuals with slight average decline (difficult to detect) especially
after age 60-70, and especially with very rapid thinking processes
- approx. 10% show improvement
in thinking and "wisdom" (experience)
- crystallized intelligence -
usually little change or improvement, resulting in increasing speed and
accuracy of intelligent mental activities in familiar situations
- fluid intelligence - usually
decreases, resulting in slower and less accurate intelligent mental activities
in novel situations
- personality - usually stable
- different personalities are better
for coping with difficult situations
- sleep - very variable among individuals, with
gradual decline in quality (more awakenings, less Stage 4 and REM)
- NOTE - daytime sleepiness that is
serious enough to interfere with normal activities is pathological, not normal
18. List methods for improving memory
functions.
- written notes, repetition, organizing information,
mnemonic devices, mental imaging, relating information to familiar experiences,
memory training programs, increasing self-confidence
19. Describe the importance of
biorhythms and average age changes in biorhythms.
- important for stabilizing and regulating regular
activities (e.g., sleep:wakefulness
periods and cycles, body temperature, blood pressure, hormone levels)
- average decreases in amplitudes and lengths of circadian
rhythms result in decreases in regularity of normal rhythmicity of body
activities and decreases in synchrony among body activities, especially sleep
patterns and quality of sleep.
20. Describe the overall effects of
nervous system age changes on the system's ability to maintain homeostasis and
quality of life.
- highly variable changes
- average gradual decline
- affects processes requiring high coordination most
- compensatory strategies can negate effects of many age
changes
21. For strokes, indicate that strokes
are diseases (not age changes), and give the following information. (p. 139)
- rank as cause of death among elderly (3rd)
- effects other than death (disability, social,
psychological, economic)
- trend in incidence ( especially after age 65)
- two main causes (atherosclerosis, heart failure)
- reasons that the two main causes produce stroke (block
vessel, brain hemorrhage)
- three main types of stroke based on time factors (TIA with
recovery within 24 hours, RIND with partial gradual recovery, completed with
little or no recovery)
- methods of preventing strokes (prevent
atherosclerosis)
22. For dementia, indicate that
dementias are abnormal (not age changes) and give the following information.
- four criteria for dementia = (1) great ¯ memory plus other high level
function, (2) seriously affects activities, (3) chronic, (4) has physical basis
- trend in incidence = increase, especially after age 60,
incidence doubles each 5 years after age 65 to reach 30%+ at age 85
- distinction between reversible dementia and irreversible
dementia
- note different incidences for moderate vs. severe forms
- % caused by atherosclerosis = 10%-20%
- % caused by Alzheimer's disease = 55%+
- other causes = parkinsonism, head trauma, medications,
malnutrition, etc.
23. Explain how multi-infarct dementia
develops.
- continuous accumulation of small dead spots in the brain
from inadequate blood flow causes gradual decline in many brain functions,
finally resulting in dementia
24. For Alzheimer's disease, provide
the following information.
- trend in incidence = with age, especially after age 65
- rare before age 40
- one percent of people under age 65
- rate doubles every five years in
people over age 60, reaching 20 percent of people over age 80
- two overall effects = disability, death
- any three specific effects in victims = ¯ short term memory, ¯ ability to perform activities of
daily living (ADLs), disorientation, ¯ learning, ¯ language functions, variations in
personality, confusion, ¯ long
term memory, ¯ self-care, ¯ motor function, death
- three effects on non-victims = expense, social upheaval,
care-giver burden
- types = (1) early onset AD, typically before age 40 (i.e.,
familial AD= FAD), (2) late onset AD, typically after age 60 (i.e., senile
dementia of the Alzheimer's type = SDAT)
- suspected causes = (1) genes, normal aging processes, head
trauma, aluminum
- time course = steady decline with 2-20 years to death
after diagnosis
- strategy for diagnosis = process of elimination, autopsy
- effects on the brain = great amyloid plaques (i.e., senile
plaques), great neurofibrillar
tangles, free radicals, inflammation, great ¯ acetylcholine, ¯ number of neurons, amyloid in vessels -> vessel
stiffness -> decreased blood flow
- treatment strategies = prevention in postmenopausal women
using estrogen supplements; relieve symptoms, treat complications, provide
support services for victim and family
25. Describe or explain how factors
found in Alzheimer's disease are believed to cause decreased brain functioning.
- beta-amyloid -> senile plaque formation, free radical
damage, inflammation, glycation, neuron death
- tau protein -> increases in neurofibrillar
tangles
- apolipoprotein-epsilon - disruption of neuron membranes,
increases formation of free radicals and plaques and tangles
- presinilins - unknown effects
26. List and describe genes influential
in the development of AD.
- genes on chromosome 21 -> increases in harmful
beta-amyloid -> FAD
- genes on chromosome 19 -> increases in harmful form of
apolipoprotein epsilon -> SDAT
- genes on chromosome 14 and on chromosome 1 -> increases
in presinilins -> FAD
27. For Parkinson disease, provide the
following information.
- trend in incidence = rare before age 50, increases
to two percent of people over age 50
- types and causes = primary Parkinson's disease (cause
unknown), secondary Parkinson's diseases (cause by other CNS abnormalities)
- any three effects = irregular control of muscle
movements resulting in tremors, rhythmic uncontrolled contractions, inability
to complete movements, slower movements, constipation, loss of balance,
insomnia, memory loss, personality and psychological abnormalities, dementia
- nervous system changes causing effects = imbalance in
neurotransmitters controlling muscle movements (e.g., Dopamine) For video clips, go to the following Internet
site
https://medweb.bham.ac.uk/http/depts/clin_neuro/teaching/tutorials/parkinsons/parkinsons2.html
(For videoclips showing the effects of Parkinson’s
disease on muscles and movements, go to https://www.youtube.com/watch?v=3wg9ExKwZy4
and https://www.youtube.com/watch?v=jclJVrLODQA.
Search https://www.google.com/ and https://www.youtube.com/ to see more
Parkinson's disease video clips.)
- time course = steady progress but variable in rate
between individuals; death some time after five years from onset
- diagnosis = measuring amount of brain dopamine, evaluating
types and progress of signs and symptoms
- treatments = supplements to increase dopamine; surgical
implantation of dopamine- producing tissues; relieve symptoms, treat
complications, provide support services for victim and family
28. Describe dementia with Lewy bodies.
- dementia associated with increases in clumps of
microfilaments (Lewy bodies) in brain neurons
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Copyright 2020: Augustine G. DiGiovanna, Ph.D., Salisbury,
Maryland
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Copyright 2020: Augustine G. DiGiovanna, Ph.D.,
Salisbury University, Maryland
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