Exam 1 Flashcards
What are the 3 types of herniation that can occur?
1) Subfalcine/Cingualte Herniation
2) Tentorial Herniation
3) Cerebellar Herniation
What 4 things can cause expansion in the brain?
Edema
Hemorrhage
Inflammatory cells
Neoplastic Cells
Cells in the brain most–>least sensitive to hypoxia
1) neuron
2) oligodendrocytes
3) astrocytes
4) microglial
5) endothelial cells
What neuron populations in the brain are most sensitive to hypoxia?
1) hippocampus
2) Cerebellum Perkinje cells
3) pyramidal neocortical neurons (middle and deep layers)
What do global hypoxic/ischemic events alter?
Hemoglobin’s oxygen carry capacity
What are two things that cause GLOBAL hypoxia?
1) anesthetic events
2) severe anemia
Name 3-4 things that cause FOCAL ischemia?
Emboli
Atherosclerotic plaques
Vasculitis
Circle of willia malformations
What are the 6 BROAD ways that the nervous system can be injured?
1) intrinsic flaws (genetic defects)
2) nutrient deficiency or excess
3) lack of oxygen
4) trauma
5) poisons
6) pathogens & autoimmune disease
4 ways genetic defects cause disease?
1) alter cell metabolism/maintenance
2) alter cell migration/maturation
3) alter elimination of metabolic products
4) produce tumors
How can defects in cell migration/maturation cause disease? (What are 4 outcomes)
1) failure to close neural tube
2) cells don’t migrate to surface
3) 2 hemispheres aren’t formed
4) gyri don’t form
What components of the nervous system are affected by genetic defects in cell metabolism?
1) neurons
2) neurons & axons
3) axons
4) myelin
What 2 things make tumors of the CNS unique?
1) can cause death when benign
2) almost never metastasize outside the CNS
How do CNS tumors cause damage?
1) direct compression/invasion of tissue
2) secondary effects (i.e. edema, hemorrhage, herniation)
How does excess/inadequate nutrition cause cell injury?
1) alters metabolism and/or synthesis of cellular constituents
2) excess nutrients can compete for binding sites
3) alters osmotic balance
Explain the pathology of thiamine deficiency
alters cell metabolism; thiamine is required by cells to synthesize ATP from food; w/o ATP cell dies
Decreased oxygen
Hypoxia
No oxygen
Anoxia
No/drastically reduced blood flow
Ischemia
What are 5 mechanisms of ischemic/hypoxic cell injury?
1) impaired energy production
2) ion influx/efflux (K out, Ca in)
3) cytoskeletal damage
4) activation of enzymes that destroy lipids, proteins, and nucleic acids
5) free radical formation
Name 3 ways trauma leads to nervous system injury
1) direct mechanical disruption
2) damage to blood vessels 3) secondary swelling
Coup vs. Countercoup
Coup–moving object hits stationary head (impact injury is worst)
Countercoup–moving head hits stationary object (recoil injury is worst)
What are the 3 categories of CNS hemorrhage?
1) subdural
2) subarachnoid
3) parenchymal
3 causes of PNS trauma
1) crushing (i.e. downer cow)
2) traction/avulsion (BP)
3) neoplastic process (in or near nerve)
Poison vs. Toxin?
Poison–any ingested, inhaled, injected, or absorbed substance that kills or injures an organism
Toxin– a poison produced by organisms in nature
