Brainscape's Knowledge GenomeTM

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


See full index

MOVEMENT NEUROSCIENCE EXAM 1 > MODULE 2- Electrical Signals of Nerve Cells > Flashcards

MODULE 2- Electrical Signals of Nerve Cells Flashcards

1
Q

what do nerve cells do

A

generate electrical signals to encode information

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

**resting membrane potential

A

the constant voltage across the membrane when the cell is at rest (40-90 mV)

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

**receptor potential

A

a change in potential when sensory neurons are stimulated

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

**synaptic potential

A

a change in potential when one neuron stimulates another across a synapse using neurotransmitters

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

**action potential

A

a nerve impulse or spike that travels along an axon

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

**passive electrical response

A

occurs without any unique neuronal property in response to a stimulus

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

**hyperpolarization

A

a stimulus that causes the membrane to become more negative than that of the resting membrane potential

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

**active electrical response

A

occurs when a stimulus causes the membrane potential to increase past threshold (threshold potential), thereby generating a depolarizing AP

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

**once threshold is reached, APs are ____

A

all or none

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

**where is stimulus intensity encoded

A

AP frequency

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

subthreshold responses of receptor potentials

A

responses are graded in proportion to stimulus strength or intensity

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

neuronal electrical signals can be transmitted over ____

A

long distances

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

poor spread of passive electrical signals is experimentally demonstrated with what

A

injection of a subthreshold current

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

passive current flow/conduction

A

decays with distance along an axon

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

long distance propagation via APs is experimentally demonstrated with what

A

injection of a suprathreshold current

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

active current flow/conduction

A

shows a constant amplitude of the AP (doesn’t decay) along an axon

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

what do anesthetic drugs interfere with

A

neuronal electrical signaling

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

3 types of anesthetic drugs

A

-local
-regional
-general

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

local anesthesia

A

-blocks pain receptor electrical signaling at the site
-blocks Na+ channels involved in AP generation

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

regional anesthesia

A

reduces pain sensation over a larger body area, such as during child delivery

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

general anesthesia

A

-causes unconsciousness or lack of sensation + muscle relaxation
-main effect is to hyperpolarize neurons, making them more difficult to excite

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

what do ion movements produce

A

electrical signals

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

**2 requirements for generating cellular electrical signals

A

-concentration gradient (difference) of specific ions across the membrane
-membrane is selectively permeable to some ions, made possible by ion channel proteins

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

what are active transporters + ion channels responsible for

A

ion movements across neuronal membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

active transport

A

move something against its concentration gradient

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

active transporters

A

-actively move selected ions against concentration gradient
-create ion concentration gradients

27
Q

ion channels

A

-allow ions to diffuse down concentration gradient
-are selectively permeable to certain ions

28
Q

simple lab experiment demonstrating electrochemical equilibrium

A

-membrane permeable to only K+
-K+ first moves down its concentration gradient
-then, it moves down its electrical gradient
-chemical + electrical forces continue to balance until dynamic equilibrium + no net movement is reached

29
Q

when is electrochemical equilibrium reached

A

when there is no further net movement of K+

30
Q

what relationship does Nernst equation predict

A

linear relationship between the transmembrane concentration gradient + the membrane potential

31
Q

what do electrical + chemical forces create

A

membrane potentials

32
Q

what is predicted by the Nernst equation + electrochemical equilibrium

A

the electrical potential generated across the membrane at electrochemical equilibrium (equilibrium potential) for a SINGLE PERMEANT ION

33
Q

2 roles of permeant ion gradients + electrical potentials in electrochemical equilibrium

A

-perform an experiment to confirm electrochemical equilibrium
-it is possible to change the ion flux by changing either the potential imposed in the membrane or the transmembrane concentration gradient for an ion

34
Q

what ions generate the resting membrane potential

A

potassium ions

35
Q

concentration gradients across neural membranes are…

A

comparable for all species investigated

36
Q

the concentration of which 4 ions gradients enable the calculateion of the Nernst equilibrium potential

A

K+, Na+, Ca2+, Cl-

37
Q

resting membrane potential of squid neuron membrane

A

-65 mV

38
Q

equilibrium potential for K+

A

-75 mV

39
Q

what is indicated by resting membrane potential of squid neuron membrane (-65 mV) is closest to equilibrium potential for K+ (-75 mV)

A

indicates the resting membrane is more permeable to K+ than any other ion

40
Q

how large is giant nerve cells of squid compared to mammalian neurons

A

100-1,000x larger
-their large size is what makes them easy to work with

41
Q

why did giant nerve cells evolve in squid

A

to evade predators

42
Q

what does the large-diameter of the squid neuron’s axon mean

A

faster than normal propagation of APs

43
Q

role of K+ in neuronal resting membrane potentials

A

-living squid neuron bathed in solution
-raise the [initial K+] until it equates [final K+] -> resting membrane potential ~ 0
-resting membrane potential varied with log [final K+] with a slope that approaches 58 mV per 10-fold change in [final K+]

-Hodgkin + Katz showed that:
-permeability to K+ is higher than for any other ion
-[final K+] > [initial K+]

-the resting membrane potential of a squid giant axon is determined by the K+ concentration gradient across the membrane

44
Q

what 2 things did Hodgkin + Katz show

A

-permeability to K+ is higher than for any other ion
-[final K+] > [initial K+]

45
Q

Goldman equation for multiple permeant ions

A

an extension of the Nernst equation, taking the [ions] gradients + their respective permeabilities into account

46
Q

during depolarization, what happens to membrane potential

A

membrane potential becomes more positive as it tries to reach the E of Na+

47
Q

during repolarization, what happens to membrane potential

A

membrane potential becomes more negative as it tries to reach the E of K

48
Q

compare permeability of K to Na for the steps of AP graph

A

-resting potential: P of K > P of Na
-depolarization: P of Na is increasing
-at top/peak of AP: P of Na > P of K
-repolarization: P of Na is decreasing
-back to resting potential: P of K > P of Na

49
Q

what do APs arise from

A

sequential changes in sodium + potassium permeability

50
Q

at rest, how permeable is neuronal membrane to Na+

A

only slightly permeable

51
Q

during depolarization + overshoot phases, how permeable is neuronal membrane to Na+

A

extremely permeable to Na+
-due to opening of Na+ sensitive channels that are closed when at rest

52
Q

what do membrane pumps ensure + why

A

ensures that [initial Na+] > [final Na+]
-so that during depolarization, Na+ rushes in toward the E of Na

53
Q

resting state is due to what

A

the high permeability of K

54
Q

depolarization is due to what

A

due to the transient increase in permeability of Na+

55
Q

all APs have what 3 things

A

-overshoot
-falling phase
-undershoot

56
Q

how do APs differ

A

differ widely in amplitude + duration of these various phases, depending on the neuron part (dendrite, axon, soma) + type (Purkinje neuron, motor neuron, etc.) from which they are recorded

57
Q

AP steps

AP steps (5)

A
  1. neuron at rest
  2. rising phase
  3. overshoot
  4. falling phase
  5. undershoot
58
Q

AP steps

  1. neuron at rest
A

(due to active transport of Na/K pump)
K+ inside > K+ outside
Na+ inside < Na+ outside

P of K > P of Na

59
Q

AP steps

  1. rising phase
A

initial depolarization due to receptor potential or synaptic potential
-increase in P of Na; Na channels open

60
Q

AP steps

  1. overshoot
A

P of K < P of Na
-Na channels open
-K channels open

61
Q

AP steps

  1. falling phase
A

P of Na decreases
-Na channels close
-K channels open

62
Q

AP steps

  1. undershoot
A

P of K > P of Na
-K channels open

63
Q

**what is permeability determined by

A

the number of ion channels that are open

MOVEMENT NEUROSCIENCE EXAM 1 (9 decks)

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