Brainscape's Knowledge GenomeTM

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


See full index

Biology 224 > Theme 6 > Flashcards

Theme 6 Flashcards

Signal Transmission in the Nervous System

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Neurons use electrical signals to communicate with:

A

neurons
muscles
glands

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

electrical signals or nerve impulses involve changes in the amount of electrical charges across a cell’s plasma membrane. This is called:

A

Membrane Potentials

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

T of F: All cells have membrane potentials.

A

True. But only neurons, muscle, and endocrine cells are excitable.

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

what types of cells are excitable?

A

endocrine
muscle
neuron

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

Why do we study squid axons?

A

Squid giant axons are used extensively to study membrane potentials.

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

What is the diameter of a typical giant axon of a squid?

A

1mm

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

what is the function of the giant axon of a squid?

A

controls part of the water jet propulsion.

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

Is the giant axon of a squid myelinated or unmyelinated?

A

unmyelinated; which decreases the conduction velocity potential substantially.

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

What decreases the conduction velocity potential of a squid giant axon?

A

it being unmyelated.

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

Voltmeter does what?

A
  1. records the voltage difference between the micro electrodes inside and outside the neuron.
  2. measure of membrane potential
  3. measurement made as a function of time.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T or F: Neurons are electrically Polarized

A

True; outside of the membrane and inside of the membrane is polarized.

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

The positive and negative “poles” of a neuron are…

A

on the inside and outside of the cell membrane.

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

What acts as a barrier that separates the charges within a neuron?

A

the plasma membrane

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

The difference in charges on the inside and outside of a cell membrane act as :

A

an electrical force measured in volts.

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

T or F : The plasma membrane is permeable to cation and anions

A

False - impermeable to cations and anions.

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

plasma membrane of a Neuron functions as:

A
  1. separates charge (on inside and outside of cell)
  2. maintains resting potential within cell. (-70mV)
  3. Negative ions within the cell are drawn to the positive ions arrayed on the outside surface of the membrane.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The resting potential inside the cell:

A

-70mV

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

Which is more negative? The interior of the neuron cell membrane or the exterior?

A

interior cell membrane

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

What type of channels do Ions move through?

A

gated channels.

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

what are the two types of gated channels?

A

Voltage-gated

Ligand-gated

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

Voltage gated channel

A

open and close in response to voltage changes

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

ligand gated channels

A

open and close in response to ligands or chemicals.

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

What are the 3 membrane factors that contribute to resting potential?

A
  1. Na+/K+ -ATPase pump
  2. Ion channels
  3. Negatively charged molecules such as proteins more abundant inside the cell.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Na+/K+-ATPase pump

A

transports 3 Na+ out for every 2K+ moved in.

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

Do ion channels need energy?

A

No.

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

Two types of Ion channels that contribute to resting potential?

A

Na+ specific channels

K+ specific channels

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

Ion channels

A

allows passive movement of ions

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

Within a neuron cell membrane, there are more ungated channels of which type? K+ or Na+

A

more K+ ungated channels than Na+ ungated channels

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

Neural membrane is more permeable to which ion at rest? K+ or Na+?

A

K+

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

What are the 3 possible states of sodium channels?

A
  1. Open
  2. Closed
  3. Inactive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

There are more K+ or Na+ in the cell?

A

K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

There are more K+ or Na+ outside the cell?

A

Na+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Membrane potential

A

the difference between the electric charges inside and outside the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Resting Potential

A

membrane potential of a cell that is not sending nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Action potential

A

membrane potential of a cell that is sending nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Electrochemical Gradient

A

combined effect of electrical and chemical gradients.

37
Q

Depolarization

A

cell membrane less polarized, less negative relative to surrounding solution.

38
Q

Hyper-polarization

A

cell membrane is more polarized, more negative.

39
Q

Gated channels open allowing Na+ to flow in and membrane potential becomes more positive (less negative) this is an example of:

A

Depolarization

40
Q

K+ moves out of the cell making the cell membrane less positive (more negative) This is an example of:

A

Hyperpolarization

41
Q

Two types of Membrane Potentials:

A
  1. graded potentials

2. action potentials

42
Q

Graded potentials

A

depolarization or hyperpolarization varies depending on strength of stimulus
occur locally on dendrites or soma
spreads a short distance and dies out
act as triggers for action potential.

43
Q

What type of membrane potential varies its polarization depending on the strength of stimulus?

A

Graded potentials

44
Q

What type of membrane potential triggers for action potential?

A

graded potentials

45
Q

Action potentials

A 
carry the electrical signal along an axon
always the large same amplitude of depolarization
All or none response (can't be graded)
Actively propagated(regenerates itself as it travels)
46
Q

What type of membrane potential is actively propagated?

A

action potentials

47
Q

what type of membrane potential always has the same large amplitude?

A

action potentials

48
Q

Action potentials are generated by what type of ion channels?

A

voltage-gated ion channels

49
Q

When do the voltage gated ion channels shut during an action potential within a neuron?

A

when the membrane potential is near the resting potential

50
Q

What causes the voltage gated ion channels to initially open?

A

when membrane potential increases to a threshold value

51
Q

Threshold potential

A

-50mV - barrier that initiates an action potential

52
Q

which voltage-gated channel opens and triggers action potential?

A

Na+ channels

53
Q

Which Ion diffusion into the cell causes the “spike” in an action potential?

A

Na+

54
Q

What happens when an action potential reaches its “spike” and the membrane is sufficiently positively polarized?

A

the Inactivation of the Na+ voltage-gated ion channels

55
Q

Absolute refractory period

A

while inactivation gate of Na+ is closed, cell is unresponsive to another stimulus.
Immediately following the firing of a nerve fiber, it cannot be stimulated.

56
Q

What is the function o the Absolute refractory period?

A

limits the frequency of action potentials and ensures action potential does not move backward toward cell body.

57
Q

What prevents an action potential from “moving backward” to the cell body?

A

absolute refractory period

58
Q

When are the Voltage-gated K+ channels opened ?

A

opened by threshold, but 1 msec later than Na+ channels

59
Q

When many K+ leave the membrane, the membrane potential…

A

hyperpolarizes

60
Q

What type of ions are actively transported out of the plasma membrane?

A

Na+

61
Q

Relative Refractory Period

A

many K+ leave cell and membrane becomes negative again.
the period shortly after the firing of a nerve fiber when partial repolarization has occurred and a greater than normal stimulus can stimulate a second response.

62
Q

When resting membrane potential is restored the voltage-gated ion channels are open or closed?

A

closed

63
Q

What as the key event that led to the formation of the nervous system?

A

evolution of K+ channels with a slightly slower opening time than Na+ channels

64
Q

what would happen if K+ and Na+ channels opened at the same time?

A

they would negate eachother’s effects

65
Q

Speed of Signal Transmission varies based upon?

A

Axon diameter

Myelination

66
Q

a broad axon provides ______ resistance

A

less

67
Q

a broad axon provides ______ moving action potentials

A

faster

68
Q

Myelinated neurons transmit signals ______ than unmyelinated

A

faster

69
Q

Saltatory conduction

A

action potential seems to “jump” from node to node (occurs in Nodes of Ranvier)

70
Q

What are the only areas of the axon that have enough Na+ channels to elicit an action potential?

A

Nodes of Ranvier

71
Q

Synapses

A

junction where nerve terminal meets a neuron, muscle cell, or gland.

72
Q

Presynaptic cells

A

send a signal into a synaptic cleft

73
Q

Postsynaptic cell

A

receives the signal

74
Q

Two different types of synapses:

A

Electrical synapses

Chemical synapses

75
Q

Chemical synapse

A

the presynaptic neuron releases a neurotransmitter that binds to a receptor located in the postsynaptic cell.

76
Q

Electrical synapse

A

the presynaptic and post synaptic cell membranes are connected by channels that are capable f passing electrical current, causing voltage changes in the presynaptic cell to induce voltage changes in the post synaptic cell. Gap Junctions**

77
Q

Which type of synapses uses gap junctions?

A

electrical synapse

78
Q

In chemical synapsis, which type of synaptic nerve (PRE/POST) contains vesicles of neurotransmitters?

A

Presynaptic

79
Q

What process, in the presynapitic nerve cell, releases neurotransmitters into the synaptic cleft?

A

exocytosis

80
Q

In chemical synapsis, binding a neurotransmitter in the synaptic cleft changes what?

A

the membrane potential of the postsynaptic cell.

81
Q

EPSP - excitatory postsynaptic potential

A

bring membrane closer to threshold potential.

82
Q

IPSP - inhibitory postsynaptic potential

A

takes membrane father from threshold potential (usually hyper-polarizes)

83
Q

When does a chemical synaptic signal end?

A

when neurotransmitter is broken down by enzymes or aken back into presynaptic cell for reuse.

84
Q

3 types of Neuron response in Chemical synapses?

A

Synaptic integration
spatial summation
temporal summation

85
Q

synaptic integration

A

integrates multiple inputs to single neuron

86
Q

spatial summation

A

when two or more EPSPs or IPSPs are generated at one time along different regions of the dendrites and cell body, their effect SUM each other.

87
Q

Temporal Summation

A

Two or more EPSPs arrive at same location in quick succession.

88
Q

Equilibrium potential

A

opposing forces of chemical and electrical gradients where there is no net movement of ions.

Biology 224 (9 decks)

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