L03 Neurophysiology II: The Action Potential

Question 1

what is the neurophysiology of multiple sclerosis?

Answer 1

demyelination of CNS axons

Question 2

what is the neurophysiology of guillain-barreé syndrome?

Answer 2

demyelination of PNS axons

Question 3

how does lidocaine work as a local anesthetic?

Answer 3

it binds to the inside of VG Na+ channels so it needs to enter through open channels first to access the binding site. thus, it selects for fibres with the most open VG Na channels. these are most common in thin, unmyelinated pain fibres.

Question 4

physical location of C6 dermatome?

Answer 4

thumb

Question 5

physical location of C7 dermatome?

Answer 5

middle finger

Question 6

physical location of C8 dermatome?

Answer 6

pinky

Question 7

innervation of ulnar nerve?

Answer 7

pinky, medial side of ring finger

Question 8

innervation of median nerve?

Answer 8

palmar side: thumb, index, middle, lateral ring

dorsal side: thumb, index

Question 9

innervation of radial nerve?

Answer 9

thenar muscle area of palm

Question 10

what’s the C3-C5 group for?

Answer 10

phrenic nucleus

Question 11

what’s the T1-L2 group for?

Answer 11

sympathetic preganglionic neurons for visceral function and skin regulation

Question 12

what’s the S2-S4 group for?

Answer 12

parasympathetic innervation of pelvic splanchnic organs. origin of pudendal nerve for external anal and urethral sphincters