PSYCH 15 Lecture Notes - Lecture 8: Motor Coordination, Microorganism, Basal Ganglia
Chapter 10: Brain Damage and Neuroplasticity
11/9/17
Causes of Brain Damage
- Brain tumors: (neoplasm)
o Cancer – cells that keep dividing uncontrollably
o 20% of brain tumors are meningiomas (encased in meninges)
▪ Eapsulated hee, so a’t spead
▪ Usually benign so can be surgically removed bc on the outside of the brain
o Most brain tumors are infiltrating
o 10% are metastatic (originated from somewhere else like the lungs)
- Cerebrovascular disorders
o Stroke: sudden event that causes brain damage
▪ Cerebral hemorrhage – bleeding in the brain
▪ Cerebral ischemia – disruption of blood supply
o 3rd leading cause of death in the US
o Most common cause of adult disability
o Hemorrhage
▪ Type of stroke
▪ Aneurysm: weak spot in blood vessel that makes a stroke more likely
• Cause: congenital (present at birth), poison, infection
o Ischemia (disruption of blood supply)
▪ Type of stroke
▪ Opposite of heohage istead of lood goig eehee, thee’s a lak of lood
▪ Thrombosis: plug forms in the brain, clog the brain, prevents the passage of brain
• Plug can be anything, very general– fat, oil, clot, tumor cells, air bubbles
▪ Embolism: plug that forms elsewhere and moves to the brain
• Traveling thrombosis essentially
▪ Arteriosclerosis: wall of blood vessels thickens, usually due to fat deposits
• Can happen in any blood vessel
▪ Does NOT happen immediately
▪ Cells do’t die of lak of lood, die of eess NT elease
• Blood-deprived neurons become overactive and release glutamate
• Glutamate overactivates its receptors (NMDA receptors) → influx of Na and Ca
• Influx of Na and Ca → release more glutamate onto postsynaptic neuron,
sequence of internal reactions that ultimately kill the neuron
▪ Takes time to occur (chain reaction)
▪ Does’t ou euall i all pats of the ai
• Some areas of the brain that are more sensitive to blood loss (hippocampus can
tolerate less blood loss than other parts of the brain)
▪ Mechanisms of damage vary with the brain structure affected
- Closed-head injuries
o Bai ijuies of los that do’t peetate the skull ai ollides with the skull)
▪ Contrecoup injuries: contusions are often on the side of the brain opposite to the blow
o Contusions – closed-head injuries that involve damage to the cerebral circulatory system
▪ Hematoma (bruise) forms
o Concussion – he thee’s a distubance of consciousness following a blow to the head and no
evidence of structural damage
▪ Can get this without a contusion
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