Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurobiology > Lecture 3 > Flashcards

Lecture 3 Flashcards

1
Q

an _____ _______ is generated by the glow of ions through voltae gated channels

A

action potential

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

t/f the nervous sustem expresses a rich variety of voltage gaed ion channels

A

true

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

t/f the opening of voltage gated ion channels is all or none

A

true

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

list the 4 phases of an action potential

A

rising phase, overshoot, falling phase, undershoot phase

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

t/f the rising and overshoot phase is potassium dependent

A

false , it is sodium dependent

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

t/f the rising and overshoot phase is sodium dependent

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

are sodium channels voltage gated

A

yes

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

define threshold potential

A

voltage at which many of the sodium channels start to open

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

does sodium move into or out of a cell during the rising and overshoot phase

A

it goes into the cell

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

during the rising and overshoot phase does hyperpolarization or depolarization occur

A

depolarization

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

is the falling and undershoot phase sodium or potassium dependent

A

potassium

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

a potassium channels voltage gated

A

yes

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

which opens and closes faster a sodium or potassium channel

A

sodium

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

during the falling phase is hyperpolarization or depolarization occuring

A

hyperpolarization

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

during which phases are sodium channels inactivated

A

falling and undershoot phase

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

can sodium channels pass current if they are inactivated

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

during the falling and undershoot phase if hyperpolarization or depolarization occuring

A

hyperpolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

when a cell is returning to resting membrane potential what channels are closing

A

the potassium channels close

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

when na channels open and na rushes in this is an example of ______

A

depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when k channels open , k rushes out this is an example of ______

A

hyperpolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

when k channels close it shuts off the hyperpolarizing or depolarizing current?

A

hyperpolarizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what did hodkin and huxley want to know

A

which ions gave rise to an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the main point of a voltage current

A

it measures current at specific voltages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

if you hold an axon at 0mv what 3 currents will you see

A
  1. very transient capacitative current
  2. fast transient current inward , rising phase
  3. delayed sustained current, outward part of the falling phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what ion is responsible for the transient current

A

sodium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

at the reversal potential is there any net movement of ions

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what does the reversal potential equal

A

the diffusional force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the name of the chemical that is responsible for blocking sodium

A

tetrodotoxin (ttx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

t/f ttx block the ouward current

A

false, ttx only blocks the early inward current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the inward current is dependent on which ion

A

sodium

31
Q

is the sustained current sodium dependent

A

no

32
Q

the sustained current is dependent on which ion

A

potassium

33
Q

what is the name of the potassium channel blocker

A

tetraethylammonium (tea)

34
Q

does TEA block early inward currents

A

no , it only blocks late outward current

35
Q

if you want to have no action potential which 2 chemicals would you use

A

tea and ttx

36
Q

changing the resting potential to a value above threshold produces what 2 effects

A
  1. an early influz of sodium into the axon , followed by sodium rapidly coming into the cell.
  2. a delayed efflus of the potassium slowly leaving the cell
37
Q

what cause a transient current

A

an early influz of sodium

38
Q

what causes a sustained current

A

delayed efflux of potassium

39
Q

ion membrane permiability changes with what

A

voltage

40
Q

t/f as you hyperpolarize you get more conductance

A

false, as you depolarize you get more conductance

41
Q

t/f an increase in sodium permiability inactivates after awhile

A

true

42
Q

t/f t/f an increase in potassium permeability inactivates after awhile

A

false

43
Q

t/f it is possible to get an action potential during an absoulte refractory period

A

false

44
Q

is it possible to get an action potential during the relative refractory period

A

yes, but unlikely

45
Q

why isnt it possible to have an action potential during the absolute refractory period

A

because sodium channels are inactive

46
Q

during the closed state of a sodium channel is the core open or closed

A

closed

47
Q

during the closed state of a sodium channel is the gate open or closed

A

open

48
Q

during the inactivated state of a sodium channel is the core open or closed

A

open

49
Q

during the inactivated state of a sodium channel is the gate open or closed

A

open

50
Q

can current flow in the inactivated state

A

no

51
Q

can current flow in the closed state

A

no

52
Q

can the closed state of a sodium channel occur when the membrane potential is low

A

no

53
Q

can the closed state of a sodium channel occur when the membrane potential is high

A

yes

54
Q

when the membrane potential is high and the channel is still shut off what do we call this state

A

inactive state

55
Q

t/f the sodium channel only lets in negative ions

A

false, the sodium channel only lets in postive ions

56
Q

voltage sensors are composed of lots of positively charged ______ _______

A

amino acids

57
Q

if a sodium channel goes from the pore being closed to open , is depolarization or hyperpolarization occuring

A

depolarization

58
Q

if a sodium channel goes from the pore being open to closed , is depolarization or hyperpolarization occuring

A

hyperpolarization

59
Q

where are action potentials generated

A

in the axon hillock

60
Q

the highes expression of sodium channels is in the

A

axon hillock

61
Q

what is the cable theory

A

if you simply inject current into a cable , the voltage will change locally, then die out as ions leak

62
Q

do action potentials decay

A

no , they are actively regenerated

63
Q

how are action potentials propegated

A

the action potential moves a short distance and triggers the opening of more sodium channels

64
Q

are action potentials able to go backwards

A

no

65
Q

why arent action potentials able to go backwards

A

because the sodium channels are inactivated

66
Q

t/f action potentials are bi directional

A

false , they are unidirectional

67
Q

what is myelin

A

an insulative material that prevents current (ions) from leaking out

68
Q

where are sodium channels located

A

at the nodes of ranviwe

69
Q

what does saltatory conduction enable

A

faster transmission of signals

70
Q

what is saltatory conduction

A

action potentials jumping from one node to the next

71
Q

does continuous conduction invovle an unmylenated axon

A

yes

72
Q

t/f myelin is only found in vertebrates

A

true

73
Q

name 2 places where mylenated axons are found

A

optic nerve and motor nerves

74
Q

name a place where unmylenated axons are found

A

olfactory nerves

Neurobiology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions