Transcript Aging and Physical Changes

Aging and Sensory and Physical
Changes
Lecture 4 – PS277
Darwin in Youth and Later Life
Lecture Outline
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Overview of aging and physical changes
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Sensory system changes
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Cardio-vascular systems and disorders
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Changes in the brain and nervous system
I. Overview of Some Primary Changes
Across Adulthood
Function:
Age of Change:
Nature of Change
Vision
Mid-40’s
Lens thickens, poorer
near vision
Hearing
Mid-50’s
Loss of high and low
tones
Smell
About 40
Poorer detection and
discrimination
Heart & Lungs
35-40
Aerobic capacity
during work
Height
40
Compression of disks
in spine
Skin
40
Wrinkling, oil
secretion poorer
Bones
35
Loss of calcium,
osteoporosis –
increased porosity
Some General Points on Physical
Aging- Nuland (2007)
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Individual variability is great
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Systems generally maintain competence despite
some losses at maximums
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Several factors: biological changes, disease,
environment, personal attitudes all interact in
predicting and explaining aging process
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These changes themselves are not diseases, but
they predispose some people to certain diseases
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Physical changes have important implications for
psychological functioning
II. Sensory Predictors of Cognitive
Functioning – Lindenberger & Baltes (1994)
III. Cardiovascular Changes with
Age
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Circulation of blood, heart, arteries, carries oxygen
from lungs
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Deposits of fat in arteries of heart, stiffening of arteries
with age (atherosclerosis)
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Heart must work harder with age, highest output
declines
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Blood pressure gradually rises with age –
hypertension can result
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None of these are diseases in themselves, just
changes with age, but make disease more likely
Chronic Conditions in Later Life
Percentages Suffering From Each Type
Canadian Adult Death Rates by
Disease Type
35
30
25
20
15
Percent
10
5
0
CV Prob
Cancer Accident
Infect
Disease
Types of Cardiovascular Disease
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Heart problems – congestive heart failure, angina
pectoris, myocardial infarction (heart attack)
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Atherosclerosis – restriction of blood flow in arteries
due to fatty deposits
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Strokes (CVAs, TIAs) – blood flow interruptions to
brain, paralysis, speech problems, risk factor for
dementia
Psychological consequences: Role of circulatory
system in brain and cognitive function – quite a direct
impact: jogging is good for health and for mind…
IV. Changes in Brain - Major
Components at Cellular Level
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Neurons: axons plus cell
bodies – electrical
pathways
Synapses =
1,000,000,000,000,000 in
brain
Dendrites = connect to
next neurons at synapses
Neurotransmitters:
chemical pathways that
cross synapses
Changes in Brain with Age
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Overall weight loss = 5%
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Some loss of neurons, but new ones can grow and
new synapses can form too
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Substantial loss of dendrites leads to some slowing
at synapses – one of the key markers of aging
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Changes in some neurotransmitters – loss in
dopamine and acetylcholine, but some increases too
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Most of these changes more marked with disease!
Some Modest Increases in AlzheimerLike Problems – Brain Sections
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Tangles: tadpoles,
axon fibres twisted
together
Plaques: blobs,
dying neurons
coalesce around
protein core
If these are common
enough, they can be
used to indicate 6
stages of Alzheimer’s
disease
Psychological Implications of Changes:
The Nun Study – Snowdon, 2001
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Followed large sample of 700 nuns from convent
in US Midwest into late adulthood
Tested every year on cognitive function, brains
were donated and studied after death
Observed physiological levels of plaques and
tangles don’t fully predict memory loss, decline
into Alzheimer’s symptoms
Some people resist expressing this behaviorally
Patterns of stroke seem to interact with these
biological markers, magnify problems
Pictures of Centenarian Nuns