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Flashcards in Neurophysiology Deck (62)
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1

peripheral neuropathy

pain and dysesthesia
-loss of sensation or reflex;weakness
-fasciculations and paresthesia

2

mononeuropathy

involve isolated neurons
-trauma or pressure

3

radiculopathy

damage to nerve roots

4

polyneuropathy

metabolites, toxins, demyelinateing disease, chronic infections

can affect axon, myelin, or synapse

5

diabetic neuropathy

hyperglycemia is trigger
-pro-oxidative and pro-inflammatory
-PNS cells more susceptible
-predominantly axonal damage
-variable demyelination

6

resting membrane potential

-65

7

synaptic potential

slow, graded, local

8

action potential

brief, actively propagated and traveling

9

equilibrium

current of ion moving in and out of cell is equal
--determined by charge and concentration

10

establishment of RMP

inward Na
outward K

-closer to K - because it has greater permeability

maintained bt Na/K ATPase pump

11

capacitor

lipid bilayer
-stores charge on opposite sides

12

resistor

ion channels
-allow certain amount of ions to flow

13

conductance

flow of ion across membrane

14

resistance

opposite of conductance

15

depolarization

due to inward Na current

16

hyperpolarization

due to outward K current

17

voltage-gated Na channels

open - membrane depolarization
inactivation - closed and will not reopen
deinactivated or resting - after membrane repolarized, return to conformation that allows them to opened in response to depolarization

18

voltage gated K channels

open - slowly, response to depolarization
-do not inactivate
resting - after membrane repolarized

19

steps in AP

depolarization
-rising phase
-falling phase
-undershoot
-resting

20

temporal summation

multiple signal over time may reinforce eachother

21

spatial summation

multiples signals that are physically close may influence eachother

22

time constant

how long to reach final voltage
-depends on number of channels
-many open channels, lower time constant

23

length constant

distance required for current to decline

24

neuromuscular junction

unmyelinated at axon
-release of acetylcholine
-muscle fiber - ligand gated ion channels

25

muscle atrophy

due to loss of trophic effect on muscle

26

fibrillation or fasciculation

neurotransmitter loss from damaged axon or schwann cells

27

peripheral nerve disease

motor - muscle atrophy
autonomic nerves - sweating lost, dry, cracked skin

28

loss of efferent autonomics

lose sweating
dry cracked skin

29

loss of afferent autonomics

changes in sensation, pain

30

internodal segment

myelin between two nodes