Brainscape's Knowledge GenomeTM

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


See full index

General Physiology (Prelims) > Electrophysiology > Flashcards

Electrophysiology Flashcards

1
Q

Ion channels: _________ proteins that span the membrane and, when open, permit the passage of certain ions

A

integral

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

Ion channels are _______; they permit the passage of some ions, but not others.

A

selective

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

the higher the probability that a channel is open, the higher the _____________, or permeability.

A

conductance

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

ligand-gated channels open and close in response to a specific ____________ (ligand) including neurotransmitters, hormones and particular ions

A

chemical stimulus

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

the _______ receptor for acetylcholine (ACh) at the motor end plate is an ion channel that opens when ACh binds to it.

A

nicotinic

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

these are ion channels that are always open

A

Leakage channels

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

the membrane’s permeability for potassium is much ________ than it is for sodium

A

higher

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

mechanically gated channels opens and closes in response to ___________ in the form of vibration (sound waves), pressure (touch) or tissue stretching.

A

mechanical stimulation

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

voltage gated channels opens in response to a change in ______________ (voltage)

A

membrane potential

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

it is a process wherein the cell interior becomes less negative due to influx of cations

A

depolarization

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

its is a process wherein the cell interior becomes more negative due to influx of anions

A

hyperpolarization

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

it refers to the number of channels that are open in a membrane; it increases when channels are opening, and it decreases when channels are closing

A

conductance

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

it is a force determined by the concentration difference across the membrane

A

concentration force

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

a force determined by the electrical difference across the membrane (membrane potential)

A

electrical force

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

At EQUILIBRIUM, these two forces are always equal
but opposite in direction

A

concentration and electrical

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

[Action potential]

the voltage-gated sodium channel is closed and not capable of opening (___________) when the membrane’s from peak to resting potential (+30 mV to -70 mV)

A

inactivated

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

[Action potential]

the voltage-gated sodium channel is open (________) when the membrane potential is from threshold to peak potential (-50 mV to +30 mV)

A

activated

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

[Action potential]

the voltage-gated sodium channel is ________ but capable of opening when the membrane potential is at resting potential (-70 mV)

A

closed

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

It is the potential difference generated across a membrane because of a concentration difference of an ion. It is generated only if the membrane is permeable to the ion

A

Diffusion potential

20
Q

At _________________, the chemical and electrical driving forces that act on an ion are equal and opposite, and no further net diffusion of the ion occurs

A

electrochemical equilibrium

21
Q

It is used to calculate the ion’s equilibrium potential at a given concentration gradient

A

Nernst equation

22
Q

Nernst equation for ions with single charge (e.g. Na +)

A

Vm = 61.5 x LOG ([ion]out / [ion] in)

23
Q

Nernst equation for ions with double charge (e.g. Ca 2+)

A

Vm = 30.75 x LOG ([ion]out / [ion] in)

24
Q

Approximate value for Na + equilibrium potential (in nerve & skeletal muscle)?

A

+65 mV

25
Q

Approximate value for Ca 2+ equilibrium potential (in nerve & skeletal muscle)?

A

+120 mV

26
Q

Approximate value for K+ equilibrium potential (in nerve & skeletal muscle)?

A

-85 mV

27
Q

Approximate value for Cl- equilibrium potential (in nerve & skeletal muscle)?

A

-85 mV

28
Q

The flux of ungated K+ channels must be an __________ from the cell

A

EFFLUX

29
Q

___________ happens when there’s too much potassium in the blood, reducing the efflux of K+ and further depolarizing the cell

A

Hyperkalemia

30
Q

_________ can accelerate the efflux of K+, hyperpolarizing the cell

A

Hypokalemia

31
Q

A CELL’S RESTING MEMBRANE POTENTIAL IS VERY
__________ TO CHANGES IN THE EXTRACELLULAR
POTASSIUM CONCENTRATION

A

SENSITIVE

32
Q

A CELL’S RESTING MEMBRANE POTENTIAL IS ______________ TO CHANGES IN THE EXTRACELLULAR SODIUM CONCENTRATION

A

NOT SENSITIVE

33
Q

property of excitable cells (i.e., nerve, muscle) that consists of a rapid depolarization, or upstroke, followed by repolarization of the membrane potential. It is propagating and an “all-or-none” process.

A

Action potential

34
Q

______ membrane potential is the result of the high resting conductance to K+, which drives the membrane potential toward the K+ equilibrium potential.

A

Resting

35
Q

The __________ is the brief portion at the peak of the action potential when the membrane potential is positive

A

overshoot

36
Q

__________ block these voltage-sensitive Na+ channels
and abolish action potentials

A

Tetrodotoxin (TTX)

37
Q

_________ blocks voltage-gated K+ channels.

A

Tetraethylammonium (TEA)

38
Q

the period during which another action potential cannot be elicited, no matter how large the stimulus.

A

Absolute Refractory Period

39
Q

period that begins at the end of the absolute refractory period and continues until the membrane potential returns to the resting level.

A

Relative Refractory Period

40
Q

occurs when the cell membrane is held at a depolarized level such that the threshold potential is passed without firing an action potential.

A

Accomodation

41
Q

_________ of action potentials occurs by the spread of local currents to adjacent areas of membrane, which are then depolarized to threshold and generate action potentials

A

Propagation

42
Q

__________ acts as an insulator around nerve axons
and increases conduction velocity. Myelinated nerves exhibit saltatory conduction because action potentials can be generated only at the _________

A

Myelin, nodes of Ranvier

43
Q

What happens during the upstroke of the nerve action
potential?

(A) there is net outward current and the cell interior becomes more negative
(B) there is net outward current and the cell interior becomes less negative
(C) there is net inward current and the cell interior becomes more negative
(D) there is net inward current and the cell interior becomes less negative

A

D

44
Q

The neurotoxin purified from the liver of a puffer fish affects which process?

A. Inhibits calcium channel
B. Opens sodium channel
C. Opens calcium channel
D. Blocks sodium channel

A

D

45
Q

A channel lined with negatively charged groups will be
selective for these ions

A. Sodium ions
B. Calcium ions
C. Chloride ions
D. Phosphate ions

A

Both A & B

General Physiology (Prelims) (4 decks)

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