Nerve Tissue Physiology

Question 1

what is considered the insulator of the nerve cell?

Answer 1

myelin

Question 2

what is the conductor of the nerve cells?

Answer 2

water with dissolved ion

Question 3

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

Answer 3

graded

Question 4

what kind of potentials happen at the axon?

Answer 4

action

Question 5

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

Answer 5

Potassium

Question 6

what does gaba stand for

Answer 6

gamma amino buteric acid

Question 7

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

Answer 7

Ca++ voltage gated ions

Question 8

why is it called a graded potential?

Answer 8

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?)

Question 9

decremental

Answer 9

will travel in both directions down the plasma membrane

Question 10

what is a seizure?

Answer 10

for some reason, an area of the brain misfires. all fire at once

• generalized tonic clonic
• absence

Question 11

what are seizure meds?

Answer 11

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

Question 12

what is the big class of anti-anxiety?

Answer 12

benzos
xanax
valium
(hyperpolarize neuronal cell membrane)

Question 13

glycine

Answer 13

inhibitory neurotransmitter

Question 14

epsp

Answer 14

excitatory which depolarizes

Question 15

ipsp

Answer 15

inhibitory which hyperpolarizes

gaba, glycine

Question 16

where does summation occur?

Answer 16

only in graded potentials

AP is all or none

Question 17

temporal summation

Answer 17

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

Question 18

spatial summation

Answer 18

two simultaneous stimuli at different locations cause EPSP to add together

Question 19

spatial summation of EPSP and IPSP

Answer 19

the two changes in membrane charges cancel each other out

Question 20

how many moving parts does the sodium channel have?

Answer 20

2

Question 21

which voltage gated ion channel is more complicated?

Answer 21

Na

Question 22

absolute refractory period

Answer 22

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)

Question 23

relative refractory period

Answer 23

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)

Question 24

hyperpolarization

Answer 24

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

Question 25

subthreshold potentials

Answer 25

graded potential didn’t get to firing first AP

Question 26

membrane AP events are not dependent on…

Answer 26

stimulus strength

Question 27

suprathreshold

Answer 27

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

Question 28

large diameter axons conduct…

Answer 28

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

Question 29

small diameter axons conduct…

Answer 29

slower

250 APs per second

Question 30

how do APs move in axons?

Answer 30

in one direction

Question 31

saltatory conduction

Answer 31

jumping from node of Ranvier to the next node

Question 32

active zone

Answer 32

on neuron end ball where ligands are ready to go

Question 33

snare and snap proteins

Answer 33

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

Question 34

what is a neural modulator?

Answer 34

aid in effect of neurotransmitter or inhibit

Question 35

autoreceptor

Answer 35

used in negative feedback system, decreases release of neurotransmitters

Question 36

axon collateral

Answer 36

outcropping of the axon

-has a role in feedback on its own self

Question 37

receptor desensitization

Answer 37

when a receptor responds once then fails to response despite neurotransmitters

Question 38

what is the best example of always excitatory neurotransmitter

Answer 38

glutamate!

• can be neurotoxic, opens too many ion channels and kills neurons
• stroke patients

Question 39

what does botox do?

Answer 39

prohibits release of acetylcholine