Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PSYC 211 > Lecture 3: The Action Potential > Flashcards

Lecture 3: The Action Potential Flashcards

1
Q

Golgi stain

A

a mixture of silver nitrate and potassium chromate that causes 2% of brain cells to darken in colour as silver chromate crystallizes inside of them, in every nook and cranny.

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

The structure of the nervous system was discovered by

A

Camillo Golgi & Santiago Ramón y Cajal. they won the Nobel Prize in 1906 for their work on the structure of the nervous system

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

Soma/ Cell body

A

Where the nucleus is located

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

Processes

A

protrusions of the neuron that extend out of the soma

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

Dendrites

A

branched, treelike extensions from the soma that are responsible for sensing the external environment (for collecting information relevant to the cell).

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

Axon

A

responsible for transmitting information (via an action potential) to downstream cells

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

Myelin sheaths

A

insulate the axon to improve the speed and fidelity of the action potential

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

Axon collaterals

A

the branches of an axon

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

Axon terminal/ Terminal Bouton

A

responsible for releasing neurotransmitters to downstream cells when there is an action potential

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

Synapse

A

The junction between an axon terminal and the membrane of a downstream neuron

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

Electrical Potential

A

The potential for electricity to flow (doesn’t mean there is actual current flowing)

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

Measuring electric potential

A

measured with glass micropipettes filled with solutions which conduct charge. The micropipette is inserted through the membrane into the cell. The voltmeter measures the difference in electrical charge between two points (the potential difference)

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

Electrical potential is measured in

A

millivolts (mV)

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

The resting membrane potential is

A

-40 and -90 mV

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

Ions

A

charged atom or molecule

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

Cation

A

positively charged ion

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

Monovalent Cation examples

A

Na+, K+

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

Divalent Cations examples

A

Ca 2+, Mg 2+

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

Anion

A

negatively charged ion

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

Monovalent anion example

A

Cl-

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

Electrostatic pressure

A

attractive force between molecules that are oppositely charged (i.e., positive and negative) or repulsive force between molecules that are similar charged (e.g., positive and positive)

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

Ion channels

A

Specialized protein molecules that sit in the cell membrane. They have a pore (hole) in them through which specific ions can enter or leave cells.

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

Leak channel

A

An ion channel protein that is in the membrane and has a pore that is always open (e.g., potassium leak channel).

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

Intracellular fluid

A

fluid contained within cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
extracellular fluid
fluid located outside of cells
26
neurons sit in and are full of ___
salt water
27
the lipid bilayer is ___ to ions
impermeable
28
If there is an equal charge of positively and negatively charged ions on either side of the membrane, then
inside of cell = 0 mV
29
Sodium-Potassium Pump goal
pumps sodium ions out of the cell and potassium ions in the cell
30
Sodium-Potassium Pump steps
1. the sodium-potassium pump binds 3 sodium ions and a molecule of ATP 2. the splitting of ATP provides energy to change the shape of the channel and drive sodium ions through the channel 3. the sodium ions are released to the outside of the membrane and the new shape of the channel allows two potassium ions to bind 4. release of the phosphate allows the channel to revert to its original form, releasing the potassium ions on the inside of the membrane
31
the sodium-potassium pump causes K+ ions to be ___ times more concentration ____ the cell than ____
30; inside; outside
32
the sodium-potassium pump causes Na+ ions to be ___ times more concentration ____ the cell than ____
15; outside; inside
33
Diffusion
Molecules move from areas of high concentration to low concentration
34
Leak Potassium Channels
the cell membrane of neurons contains K+ leak channels that are selectively permeable to K+. allows K+ to move out of the cell & along the concentration gradient. sets up the negative resting membrane potential
35
If K+ was the only ion that could cross the membrane, the electrical potential of the membrane would settle at
-90mV
36
the more K+ leak channels a neuron has, the closer the membrane potential will be to
-90 mV
37
Membrane potential
the difference in electrical potential inside and outside the cell
38
Why is the resting potential of most neurons less than -90mV
because other ions can sneak through other types of leak channels
39
Resting potential
The membrane potential of a neuron when it is not being altered by signalling molecules that cause excitatory or inhibitory postsynaptic potentials
40
Receptors
proteins found in the cell membrane that act as sensors
41
T or F: Many receptors on the neuronal membrane are ion channels that allow ions to flow through
T
42
Depolarization
When the membrane potential of a cell becomes less negative than it normally is at rest
43
T or F: Potassium can always flow through the potassium leak channels in either direction
T (but will usually flow out due to the concentration gradient)
44
Sodium Channel
Opens in response to a nerve impulse (when the membrane potential reaches -40 mV). the influx of Na+ depolarizes the membrane and opens more Na+ channels, causing the membrane potential to shoot up to +40 mV
45
T or F: The sodium channel is inactivated for a brief period following activation
T
46
The Action Potential
A brief electrical impulse that provides the basis for the conduction of information along the axon
47
Threshold of excitation
value of the membrane potential that must be reached
48
The Action Potential Steps
1. Sodium channels open 2. Potassium channels open 3. Depolarization 4. Sodium channels close 5. Repolarization 6. Potassium channels begin to close
49
Potassium Channel
Start to open on the upswing of the action potential (when the membrane potential reaches above 0 mV). The outflux of K+ through these channels, driven now by diffusion and electrostatic forces, drives the membrane potential back down within a millisecond
50
Refractory period
post action potential hyperpolarization
51
Repolarization
When the membrane potential of a cell becomes more negative than it normally is at rest
52
Wire electrode
placed in the extracellular fluid; it is an electrical conductor that provides a path for the electricity to enter or leave the medium
53
Fine glass microelectrode
inserted into the axon to record the activity of a neuron
54
Oscilloscope
a sensitive voltmeter that turns electrical fluctuations into visible signals
55
Calcium Channels
When the action potential arrives at the axon terminal, Ca 2+ channels open, causing it to enter the axon terminal. The influx of calcium causes several synaptic vesicles to simultaneously fuse with the presynaptic membrane.
56
Calcium is ___ times ___ concentration outside the cell than in
1000; more
57
Synaptic transmission
transmission of messages from one neuron to another via the presynaptic release of a neurotransmitter that crosses the synapse and binds to receptors located on the postsynaptic membrane.
58
conduction of the action potential
the movement of information along the axon
59
T or F: Conduction of an action potential can happen in either direction
false
60
T or F: the size of the action potential remains constant
true
61
all-or-none law
action potentials occur or don't occur and once triggered, they will propagate down the axon without growing or diminishing in size to the end of the axon
62
rate law
the strength of the stimulus is represented by the rate of the firing axon
63
the sodium-potassium pump requires
ATP
64
t or f: potassium leak channels are always open
t
65
neuron function
orchestrate and control the movement of the multicellular organism
66
ways neurons transmit information
electrically and chemically
67
electrical signalling
relies on changes in the membrane potential (Vm), the difference in charges inside and outside the cell
68
chemical signalling
relies on the release of neurotransmitters at the axon terminals onto other neurons
69
cytosol
the salty solution that fills the cell
70
In what direction do potassium leak channels go?
both
71
what is the threshold of excitation?
-55 mv
72
at the peak of the action potential, the membrane potential is
40 mv
73
when do potassium channels open?
on the upswing of the action potential (around 0 mv)
74
how would you widen an action potential?
by infusing a voltage-gated channel antagonist

PSYC 211 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions