MIDTERM 1 (Textbook) Flashcards
Describe different types of brain tumors (7 types)
Encapsulated tumor - tumors that grow within their own membrane
Meningiomas - tumors that grow between the meninges
Benign tumors - tumors that can be surgically removed w/ little risk of further growth in the body
Infiltrating tumors - tumors that grow diffusely through surrounding tissue
Malignant tumors - tumors difficult to remove\destroy, continues to grow after removal
Gliomas - malignant tumors developed from glial cells
Metastatic tumors - tumors carried to the brain by the bloodstream from some other part of the body
Describe differences between the two types of stroke: cerebral hemorrhage and cerebral ischemia
cerebral hemorrhage - cerebral blood vessel ruptures and blood seeps into the surrounding neural tissue that causes damage
cerebral ischemia - disruption of the blood supply to an area of the brain. Takes a while to develop; some neurons in the hippocampus specially susceptible
Describe the two sorts of closed-head TBIs
Contusions - damage to the cerebral circulatory system resulting in internal hemorrhaging (brusied brain)
mild TBI (mTBI) - Disturbance of consciousness following a blow to the head with no evidence of a contusion or oter structural damage
Describe two different types of infections of the brain
Bacterial infections - often leads to cerebral abscesses (pockets of pus in the brain)
Viral infections - 2 types: affinity or no particular affinity for neural tissue
Describe three different types of neurotoxins
heavy metals - eg. mercury + lead
antipsychotic drugs - patients developed tardive dyskinesia from taking antipsychotic drugs for schizophrenia
endogenous - eg. cortisol, antibodies, glutamate
Discuss the symptoms of Down syndrome and what causes this disorder
Associated with extra chromosome 21 created in the egg during ovulation
Consequences: characteristic disfigurement, intellectual disability, early-onset Alzheimer’s disease
Explain the difference between apoptosis and necrosis
Apoptosis - programmed cell death, gradually occurs through the shrinkage of the cell body resulting in blebbing (no inflammation, damage nearby is minimal)
Necrosis - passive cell death from injury, damaged neuron swells and breaks (from dendrites + axon to cell body) within a few hours, results in inflammation and damage to nearby cells
Explain the various types of neural degeneration that ensue following axotomy (3 types)
Anterograde degeneration - degeneration of the distal segment (axon), occurs quickly
Retrograde degnereation - degeneration of the proximal segment (cell body), occurs gradually
Transneuronal degeneration - degeneration from damaged neurons to neurons that are linked to them by synapses (can be anterograde or retrograde)
Compare neural regeneration within the CNS vs. the PNS
CNS - little regneration due to oligodendrocytes and astrocytes inhibiting growth factors
PNS - capable of regeneration due to Schwann cell myelination, producing neurotrophic factors
Describe 3 examples of cortical reorganization following damage to the brain, and discuss the mechanisms that might underlie such reorganization
- Primary visual cortex neurons become receptive to fields in the area of the retina next to the lesioned retina
- Cortical face representation expands into the original arm area after severing contralateral arm sensory neurons 10 years prior
- Motor cortex that had previously elicited vibrissae movement now activated other face muscles after transecting them
Mechanisms: 2 ways -> strengthening of existing connections (fast) + establishment of new connections by collateral sprouting (slow)
Describe the concept of “cognitive reserve” and discuss the potential role of adult neurogenesis in recovery following CNS damage
Cognitive reserve - An equivalence to education + intelligence, can be used to accomplish tasks that original brain areas cannot do
Adult neurogenesis - genesis of new neurons in the hippocampus and subventricular zone, is induced by brain damaged, could play a role in recovery from damage
Discuss early work on neurotransplantation for the treatment of CNS damage
Bilateral transplantation of fetal substantia nigra cells were successful in treating the MPTP monkey model of Parkinson’s disease through the innervation of the transplanted cells to adjacent striatal tissue, which released dopamine and alleviated severe poverty of movement, tremor, and rigidity
2 positive effects from the study: curtailed prematrue clinical use of neurotransplantation to treat human patients, stimulated researchers to take a careful look at the effects of various kinds of neurotransplantation in animal models
Discuss the methods and findings of modern research on neurotransplantation
Use of pluripotent cells (potentially induced from human skin cells w/ more research create cells for neurotransplantation)
Mechanisms of therapeutic effects in many cases are neuroprotective
Discuss methods of promoting recovery from CNS damage through rehabilitative treatment
Constraint-induced therapy - restraining the functioning arm while the affected arm receives intense training (treating strokes)
Treadmills - support of patient with harnes over moving treadmill and gradually reduce support (treating spinal cord injury)
Enriched enviroments - environments designed to promote cognitive and physical activity show to have health promoting effects
Feedback apparatus - used to treat phantom limbs by allowing the patient to move their phantom limb through a mirror and relieve the pain of the amputated limb
