Electrical properties Flashcards

1
Q

Where is resistance located in the axon?

A
  1. In the fluid INSIDE the axon

2. Across the cell membrane

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

What effect will increasing diameter have on resistance?

A

Decrease resistance

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

How is resistance decreased across the cell membrane?

A

Ion channels (allow ions to move freely)

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

Ion channel specific to sensory neurons; Located on dendrites; Channels open or close in response to some sensory stimulus (temp, light, etc.); Cause local potentials

A

Modality-gated ion channels

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

Ion channels that open in response to neurotransmitter or drug binding; Located on post-synaptic terminal; Cause local potentials

A

Ligand-gated ion channels

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

Ion channels that open or close in response to changes in the membrane potential; Channels will only let specific ions pass; Located on axons and presynaptic terminals; Important for: action potentials and release of neurotransmitters from the presynaptic terminal

A

Voltage-gated ion channels

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

The inside of an axon is usually more [negative/positve] compared to the outside. Where are Na, K, Cl, and Ca most located?

A

Negative; K= inside; Na, Cl, Ca = outside

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

The equilibrium potential is [positive/negative] for Na. The equilibrium potential is [positive/negative] for K. The equilibrium potential is [positive/negative] for Cl.

A

Positive; Negative; Negative

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

When ion channels open in a resting neuron, which way does sodium move? Potassium? Chloride? Calcium

A
Na = moves into cell
K = moves out of cell
Cl = moves into cell
Ca = moves into cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sodium-potassium ATPase pumps __ Na+ ions out and __ K+ ions in.

A

3; 2

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

Local potentials, or graded potentials, in sensory neurons are called _______ potentials. What type of ion channels are in sensory neurons?

A

Receptor potentials; Modality-gated

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

Local potentials, or graded potentials, in post-synaptic membranes are called _______ potentials. What type of ion channels are in post-synaptic membranes?

A

Synaptic; ligand-gated

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

______ refers to the inside of the cell becoming more positive where ______ refers to the inside of the cell becoming more negative

A

Depolarizing; hyperpolarizing

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

Sequential local potentials can add together on one neuron

A

Temporal summation

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

Different local potentials that occur at the same time can combine from more than one neuron; The effect can be additive or subtractive

A

Spatial summation

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

Large, brief depolarization that is repeatedly regenerated along the length of an axon; Actively propagated, so it travels long distances along the axon without a decrease

A

Action potentials

17
Q

What does a strong stimuli increase in terms of APs?

A
  1. Increases the frequency of action potentials in one neuron
  2. Increases the number of neurons that are activated
18
Q

Sodium ion channels quickly open due to ____ and close ____

A

Voltage; spontaneously

19
Q

Potassium ion channels remain open as long as the membrane is _______ and close who the membrane is _______

A

Depolarized; hyperpolarized

20
Q

No stimulus, no matter how strong, can produce a second action potential

A

Absolute refractory period

21
Q

A larger than normal stimulus can produce a second action potential

A

Relative refractory period

22
Q

What are the roles of a relative refractory period

A
  1. Allows APs to occur at greater frequency (do’t need to wait for another to occur)
  2. APs will only go in one direction
23
Q

How can you in increase the speed of APs?

A
  1. Increase membrane resistance (myelination)

2. Decrease resistance inside the neuron (larger axon/dendrite spine diameter)

24
Q

In terms of Na ion channel density, where are they most concentrated? where are they least concentrated?

A

Nodes of Ranvier; internode region

Increases the speed of AP dramatically

25
In myelinated axons, is the speed of the AP the same throughout the axon?
No, APs slow at the nodal regions where APs are regenerated
26
What will happen to the equilibrium potential for potassium in a hypokalemic patient?
increase (more negative)
27
What will happen to the membrane potential for potassium in a hypokalemic patient?
increase (more positive)
28
Will a neuron become more or less excitable in a patient with hyperkalemia?
more excitable