Lecture 17

Question 1

absolute & relative refractory period

Answer 1

absolute refractory period
Na channel inactivated

relative refractory period
voltage gated K channel open, overshoot resting level

determine how fast

Question 2

how send info

Answer 2

not by size or length
pattern, frequency(eg.pressure on skin), timing(do not send info until stimulus is applied)

Question 3

naturally occurring neurotoxin

Answer 3

tetrodotoxin河豚毒素
puffer fish河豚, inhibitor or Na channel

batrachotoxin箭毒蛙碱
phyllobates箭毒蛙 skin, Na channel activator, seizure

Question 4

therapeutically drugs

Answer 4

local anesthetics
lidocaine利多卡因, inject to jaw
benzocaine苯佐卡因
tetracaine丁卡因
cocaine可卡因

antiepileptics
phenytoin/ dilantin苯妥英
carbamazepine/ tegretol卡马西平

Question 5

slow transmit eg.

Answer 5

C fiber, put on hot pot, jolting pain

Question 6

fast transmit

Answer 6

invertebrate
fatter axon(eg.squid giant axon 1000 times fatter than our axon)

vertebrate& higher invertebrate
myelin
Schwann cell in PNS, oligodendrocyte in CNS
node of Ranvier
high conc of voltage gated Na channel

Question 7

disease related to myelin

Answer 7

multiple sclerosis渐冻症
b/c myelin degrade

Question 8

white matter& gray matter

Answer 8

white: mostly myelinated axon
gray: cell body, dendrite, synapse

Question 9

synapse 4 types

Answer 9

spine synapse: dendrite, excitatory
shaft synapse: inhibitory
axonsomatic: cell body
axoaxonic: presynaptic terminal