damage/disorders of myelin

Question 1

importance of myelin

Answer 1

• critical element for neural communication
• increases speed of conductivity by 50%
• tracts and nerves need myelin to move messages

Question 2

diffuse axonal injury

Answer 2

• twisting, tearing, shearing of the myelin and the axon itself
• cytoskeleton of the axon becomes misaligned, swells and becomes incapable of conveying messages
• eventually disconnects and is done
• due to sheer force of impact

Question 3

demylination diseases

Answer 3

• loss of integrity/presence of myelin sheath
• axon cannot transmit as quickly or at all
• if there is no use of this nerve and its connections… it is pruned away and discarded

Question 4

autoimmune/inflammatory diseases

Answer 4

• MS
• guillain barre
• encephalitis

Question 5

multiple sclerosis

Answer 5

• caused by autoimmune inflammatory response
• deterioration of myelin and replaced with plaque in CNS
• atrophy of the corpus callsum

Question 6

guillain barre

Answer 6

• autoimmune attack of myelin system of peripheral nerves
• rapid onset;may be fatal; long recovery
• very rapid onset, paralyisis of all muscles

Question 7

encephalitis

Answer 7

HIV-complex related; following childhood disease

Question 8

white matter ischemia

Answer 8

• far away ends of arteries are more susceptible to ischemic events
• white matter may become deprived of sufficient blood supply
• dysfunction, deterioration of cellular integrity negatively impacts capacity to myelinate

Question 9

-peripheral arterioles

Answer 9

conveys blood supply to the white matter