Nerve Tissue Physiology Flashcards Preview

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Flashcards in Nerve Tissue Physiology Deck (39):
1

what is considered the insulator of the nerve cell?

myelin

2

what is the conductor of the nerve cells?

water with dissolved ion

3

what kind of potentials happen at the dendrites and cell body?

graded

4

what kind of potentials happen at the axon?

action

5

movement of which ion is the key factor for cell membrane gradient?

Potassium

6

what does gaba stand for

gamma amino buteric acid

7

what kind of ion channels are at the end balls of the axon?

Ca++ voltage gated ions

8

why is it called a graded potential?

many stimulations are coming into the neuron and the graded potential allows the neuron to decide when to create an AP (does it reach the threshold or not?)

9

decremental

will travel in both directions down the plasma membrane

10

what is a seizure?

for some reason, an area of the brain misfires. all fire at once
-generalized tonic clonic
-absence

11

what are seizure meds?

gaba agonists (Cl hyperpolarizes neuron so it doesn't misfire)

12

what is the big class of anti-anxiety?

benzos
xanax
valium
(hyperpolarize neuronal cell membrane)

13

glycine

inhibitory neurotransmitter

14

epsp

excitatory which depolarizes

15

ipsp

inhibitory which hyperpolarizes
(gaba, glycine)

16

where does summation occur?

only in graded potentials
AP is all or none

17

temporal summation

how frequently one neuron is releasing neurotransmitter onto our neuron
-close enough frequency that causes an AP

18

spatial summation

two simultaneous stimuli at different locations cause EPSP to add together

19

spatial summation of EPSP and IPSP

the two changes in membrane charges cancel each other out

20

how many moving parts does the sodium channel have?

2

21

which voltage gated ion channel is more complicated?

Na

22

absolute refractory period

time in which another AP cannot be fired no matter how much stimulus it has
(Na channel has to close inactivation gate and return to where activation gate is blocking)

23

relative refractory period

time frame in which you could fire another AP, but you have to have a stronger stimulus than usual (during hyperpolarization, you need a stronger stimulus)

24

hyperpolarization

end stage of the AP when K channels are slow to close

25

subthreshold potentials

graded potential didn't get to firing first AP

26

membrane AP events are not dependent on...

stimulus ***strength***

27

suprathreshold

graded potential gets an AP, but doesn't make a greater AP...they all look the same (it will only change frequency)

28

large diameter axons conduct...

faster
1000 APs per second
larger diameter fibers offer less resistance to local current with more ions flowing per unit time

29

small diameter axons conduct...

slower
250 APs per second

30

how do APs move in axons?

in one direction

31

saltatory conduction

jumping from node of Ranvier to the next node

32

active zone

on neuron end ball where ligands are ready to go

33

snare and snap proteins

complex of cytoskeletal proteins that come together so that you pull it open to have a gap to release exocytosis

34

what is a neural modulator?

aid in effect of neurotransmitter or inhibit

35

autoreceptor

used in negative feedback system, decreases release of neurotransmitters

36

axon collateral

outcropping of the axon
-has a role in feedback on its own self

37

receptor desensitization

when a receptor responds once then fails to response despite neurotransmitters

38

what is the best example of always excitatory neurotransmitter

glutamate!
-can be neurotoxic, opens too many ion channels and kills neurons
-stroke patients

39

what does botox do?

prohibits release of acetylcholine

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