NERVOUS SYSTEM CHANGES Flashcards
THE ABILITY FOR THE NERVOUS SYSTEM TO CHANGE
NEURAL PLASTICITY
the ability to make neural structural and functional changes in response to internal and external demands
neuroplasticity
adult brain weight attained at what age?
puberty
At birth, brain weight ____% of adult brain
25%
During childhood, brain growth is related to
stages of cognitive development and language development
Decline in brain weight begins at age ____
20
Majority of loss of brain mass occurs in _____ matter
white
Total of ______% of brain weight/volume lost throughout the lifespan
15%
During _______period, maximum # of neurons & glial cells are produced
prenatal
Dendritic branching reaches adult levels of complexity from __ to __ years of age
12 – 16
After age 30, _____(area of brain)______shows 30% decrease in # of neurons
hippocampus
- Some brain structures do not show any significant loss of neurons:
- Basal ganglia
- areas related to vital functions
__________ _________may be a more dominant age-related change than overall decrease in the number of neurons
Neuronal shrinkage
May be related to forgetfulness
With aging, changes in glial cells occur:
- Increased number of astrocytes & microglia
- Decreased number of oligodendrocytes (production of myelin in the central nervous system)
true or false: dendrites continue to grow during older adulthood
(dendrites receive signals from other cells)
true
CNS still able to adapt into 70’s and longer
______ _________ can be used as a measure of
functional maturation of brain
glucose metabolism
Rate of glucose utilization is ____lower in infancy than in adulthood
30%
Myelination of PNS is complete at ____
birth
does NCV increase or decrease after birth?
increases quickily
slows with aging
Sensory NCV begins to decline after age
30
Older adults have decreased:
- Reaction time
- Attention
- Working Memory
REACTION TIMES consists of 3 parts:
which part takes the longest to execute?
- Sensory transmission of input
- Motor execution time
- Central processing: 80% of total RT
Slowing of RT in older adults due to:
- Decrease in motor NCV = 4%
- Decrease in sensory NCV = 10%
- Decrease in central processing = greatest contributing factor
Different types of memory develop at different points in time:
- Implicit: first few months
- Explicit: 8 - 12 mo
- Working: begins at 12 mo increases at 6-24 yr
- Long-term: Over lifespan
Crystallized intelligence:
- Experiential learning, education & stored information
- Ability to use judgment to decide course of action
- To understand one’s intellectual & cultural heritage
Diferences between CRYSTALLIZED and FLUID intelligences:
- Crystallized: can be affected by the environment and the attitude of the individual. Can increase during the entire lifespan with self-directed educations
- Fluid: independent of instruction or environment. Declines throughout adulthood.
Ability to form novel associations, think abstractly, reason logically, solve problems, comprehend new information
Fluid intelligence
declines throughout adulthood
Intellectual ability peaks between ____and ____yrs
of age
20 and 30
“Terminal drop” in cognitive function:
- Research : decline in IQ scores within year prior to death
True or false: Dementia can be reversible or irreversible
True
Alcohol use, TBI
Persons with evidence of cognitive impairment who do not meet present clinical criteria for dementia
Benign Senescent Forgetfulness
Mild but measurable impairment in thinking skills without the presence of dementia:
Mild Cognitive Impairment (MCI)
Progressive, degenerative disease that attacks brain cells and results in impaired memory, cognition and functional abilities. One of many causes of dementia:
Alzheimer’s Disease (AD)
What is the cause of Alzheimer’s disease?
- Not know
- Suspected to be genetic predisposition
ALZHEIMER’S DISEASE RISK FACTORS:
- Age
- One apolipoprotein E4 allele
- Fewer years of formal education
- Head trauma
- HTN
- High cholesterol
- Family history
True or false: Recent evidence that balance & gait dysfunction occur earlier in Alzheimer’s disease process than traditionally thought
true
ALZHEIMER’S DISEASE PATHOLOGY:
- Neuritic (amyloid) plaques
- Neurofibrillary tangles
Alzheimer’s brain changes include:
- Decreased size
- Narrow gyri
- Wide sulci
- Seen especially in frontal & temporal lobes
Definitive diagnosis of Alzheimer’s disease is only possible with examination of ____
brain tissue
FAST = Functional Assessment Staging Scale
for people with Alzheimer’s disease
________ learning & memory remain intact later into the Alzheimer’s disease process
implicit/procedural
these 3 tests have been found to be reliable measures in individuals with Alzheimer’s Disease (IWAD)
- TUG
- 6MWT
- Gait Speed
True or false: Physical Activity: can alter progression of AD related neuropathology and cognitive decline
true
Dendritic branching reaches adult levels of complexity
from _______ years of age
12 – 16
