Action Potential Flashcards

1
Q

The nervous system sends both:

A

qualitative and quantitative information; uses combination of electrical and chemical signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

At what part of a neuron are action potentials generated

A

axon hillock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Depolarization means

A

positive and negative numbers are flipped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what do the plasma membrane of the nerve cell body and dendrites (somatodendritic domain) resemble

A

the basolateral plasma membrane domain of a polarized epithelial cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What do the plasma membrane of the axon and its nerve terminals resemble

A

the apical domain of an epithelial cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where do you see a graded (local) response

A
  1. in dendrites and cell body; only see PASSIVE spread of voltage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where do you see an all or none response

A

from axon hillock to terminus: refers to production of action potentials due to Na and K voltage gated channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does calcium do

A

releases neurotransmitters that are stored in nerve termini which bind to receptors on next order neuron w

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is hyperpolarization

A

a membrane potential more negative than at rest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is a hyperpolarizing stimuli due to

A

either an efflux of cations or an influx of anions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is depolarization

A

a membrane potential less negative or postive than at rest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a depolarization stimuli due to

A

either an influx of cation or an efflux of anions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is threshold potential

A

the level of depolarization that triggers an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is action potential

A

a rapid, large regenerative depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the amplitude of the voltage deflection across the membrane proportional to

A

the amplitude of the stimulus pulse (the current); the larger the stimulus, the larger the voltage deflection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is resting potential

A

potential maintained across membrane of excitable cells (neurons, muscle)

17
Q

what is summation

A

when you inc or dec a graded potential in order to fascilitate or prevent an active potential to be generated

18
Q

Active potential is not summated

19
Q

What is graded potential

A

Does not generate an action potential; its amplitude varies based on strength of stimuli; it can occur all along the axonal domain as long as any depolarization is less than the threshold.

20
Q

Action potentials are:

A

all or none responses; needs to reach threshold or be above, it cant be below threshold.

21
Q

What type of signal does a graded potential recieve? what about action potential

A

input; conduction

22
Q

Where does graded potential occur? what about action potential?

A

dendrites and cell body; trigger zone through axon

23
Q

what types of gated ion channels involved in graded potential? what bout action potential?

A

Na+, Cl- Ca+; Na and K

24
Q

What type of signal does a graded potential recieve? what about action potential?

A

depolarizing or hyperpolarizing; depolarizing

25
what are the phases of the action potential
1. rising phase 2. falling phase 3. after-hyperpolarization
26
what is the depolarizing phase
Opens up Na+ channel; starts pouring into cell.
27
What is the repolarizing phase
voltage becomes more neg bc you inactivate sodium channels and you open K+ channels
28
what is the hyperpolarization phase
K+ channels slowly closing, and Na+ channels go from inactive state to closing state.
29
What are three states of voltage gated sodium channels
1. Open 2. Closed 3. Inactive
30
The positive feedback loop associated with the opening of the voltage gated Na channel is known as the:
Hodgkin cylce
31
what does refractory period refer to
unresponsive state; when membrane is refractory its because the voltage gated Na channels are in their inactive state and unable to open in response to a new depolarizing stimulus.
32
what is the one exception to the "all or none" law and the only time you would expect to see a non maximal voltage deflection during an action potential
relative refractory period; a smaller than normal height AP may be generated in response to a larger than usual stimulus.