Aging of the Nervous System Flashcards
1
Q
Changes with Aging
A
- Decreased # of sensory receptors
- Decreased synthesis of neurotransmitters
May have decreased control of: Emotions and/or Attention - Reduction of Serotonin
- Reduced memory
- Sleep pattern effects
- Thermoregulation
2
Q
Senile plaques
A
- Extracellular deposits of amyloid (starch-like protein-carbohydrate complex) in the gray matter of the brain
- Occur most often in the cortex and hippocampus
- Associated w/ AD and Dementia
3
Q
Proportion of people with plaques
A
- Age 60 years (10%)
- Age 80 years (60%)
Increases with age
4
Q
Neurofibrillary Tangles
A
- Pathological accumulation of paired helical filaments
- Found primarily in the cytoplasm of nerve cells of the brain
- Cerebral cortex and hippocampus
- Found in higher concentration in older adults
- Occurs in Alzheimer’s disease and Dementia
5
Q
Vestibular system changes
A
- Hair cell receptors decline beginning at age 30
- Vestibular receptor cells decrease by age 55-60
- Myelinated fiber loss in vestibular system is 40% by age 80
- **May lead to c/o dizziness
6
Q
Somatosensory system changes
A
- Decreased # of unmyelinated and myelinated nerve fibers
- Blood vessels become atherosclerotic -> loss of blood supply to nerve fibers
- -Major contributor to increased prevalence of peripheral neuropathies in older adults
7
Q
Motor system Changes
A
- Loss of alpha MN
- -Remaining αMN will innervate the denervated muscle cells
- -Results in larger motor units, which can effectively reduce motor coordination for finely tuned movements
- Space b/w nodes of Ranvier is reduced -> reduced NCV
8
Q
Autonomic NS Changes
A
- Reduce sympathetic control of vasculature in the skin
- Results in reduced wound repair efficiency
9
Q
Anatomic NS Changes with Age
A
- Overall brain weight decreases with age
- By 8th decade, NCV can decrease by 10-15% especially in myelinated nerves
