Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Nervous System Overview and Action Potentials > Flashcards

Nervous System Overview and Action Potentials Flashcards

1
Q

what is the difference between NS and ES?

A

NS is a quick fix to homeostatic disturbance and ES is a slower and long term maintenance.

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

what is neuroglia?

A

support cells for neurons

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

what are nissl bodies?

A

they are clusters of ribosomes found inside the cell body. So many present that the axon appears grey..

Lots of nissl bodies in grey matter

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

Whare are oliogdendrocytes?

A

what forms the myelin for axons in CNS

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

What are Schwann cells?

A

what forms the myelin for axons in PNS

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

what is the function of myelinated axons?

A

to speed up the rate of nerve impulse conduction aka SALTATORY CONDUCTION

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

what makes up a anaxonic neuron?

A

hard to tell the difference between dendrite and axon but they’re all connected to the cell body

USED FOR INTERNEURONS

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

what makes up a bipolar neuron?

A

one dendrite, one axon, and a central cell body

FOUND IN SENSORY NEURONS

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

what makes up a pseudounipolar neuron?

A

dendrite is continuous with the axon. Cell body is off to one side.

FOUND IN SENSORY NEURONS

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

What makes up a multipolar neuron?

A

Multiple dendrites attached to a cell body, a primary axon

FOUND IN MOTOR AND INTERNEURONS

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

what are the functional classifications of neurons?

A
  • sensory
  • motor
  • interneurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what division of NS are sensory, motor and interneuron a part of

A
  • Sensory: afferent division of PNS
  • Motor: efferent division of PNS
  • interneurons: ONLY in CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how do sensory neurons carry information

A

from reflex receptor to CNS

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

how do motor neurons carry commands?

A

from CNS to EFFECTORS

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

where are the cell bodies/dendrites located for sensory and motor neurons?

A

Sensory: dendrites/cell body in PNS

Motor: dendrites/cell body in CNS

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

how do interneurons carry information?

A

from one neuron to another

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

that direction does information flow in?

A

one direction

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

what are the two types of electrical signals in neurons?

A

action potential and graded potential

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

what are some examples of graded potentials

A

EPSPs and IPSPs

20
Q

what are the differences between graded and action potentials

A

GP: longer lasting, small changes in Vm, travel short distances

AP: very fast changes in Vm, always the same with non change in strength or size as they travel along membrane.

21
Q

What does depolarization mean?

A

becomes more positive, EPSPs

22
Q

What does repolarization mean?

A

Vm returns to resting value

23
Q

What does hyperpolarization mean?

A

Vm becomes more negative than resting, IPSP

24
Q

how does depolarization occur?

A

Na+ moving into the cell through open voltage-gated Na+ channels through positive feedback

25
Q

What happens at the peak of AP

A

VG Na+ channels close and slow voltage gated K+ channels open

transition from graded potentials to AP AT AXON HILLOCK

26
Q

what happens when a threshold is met for AP

A

EPSP reaches threshold and causes voltage gated Na+ channels to open

27
Q

what happens during repolarization

A

K+ moves outside of the cell, through open VG K+ channels

28
Q

what happens during hyperpolarization

A

VG K+ channels are still open and then they begin to close

29
Q

What is the V-gate Na+ activation gate?

A

Closed at resting Vm and they quickly open at threshold depolarization

30
Q

What is the V-gate Na+ inactivation gate?

A

They open at resting Vm and slowly close at threshold depolarization

31
Q

will the V-gate Na+ inactivation and activation gate be open at the same time?

A

Yes since activation opens quickly and inactivation closes slowly they overlap

32
Q

in what conditions with the V-gate Na+ inactivation gate work under?

A

will ONLY function again if the channel is back at the resting membrane potential, will not be functioning unless at rest.

33
Q

V-gate K+ channel how does it work?

A

begins to open at the threshold, but it is SLOW. Delayed by the same time as the V-gated Na+ inactivation gate

34
Q

the activation of Na+ channels during an AP occur in a positive or negative feedback? How?

A

POSITIVE. Na+ channel activation gates open rapidly. Na+ enters the cell. Which causes more depolarization of the cell. This means more Na+ channels get activated.

35
Q

What stops a Na+ channel during an AP?

A

The slower Na+ channel inactivation gate closes

36
Q

How does the absolute refractory period work?

A

IMPOSSIBLE FOR CELL TO FIRE ANOTHER AP. This is due to an all or none activation and the V-gated Na+ channels closed inactivation gates.

37
Q

How does the relative refractory period work?

A

A larger than normal EPSP and elicit an AP. This is due to some Na+ channels resetting to resting state. After hyperpolarization

38
Q

what keeps the AP flowing in one direction

A

the absolute and relative refractory periods

39
Q

How does hyperkalemia influence neuron excitability

A

increase of K+

If inbetween 3.5 and 6: There is an increase of K+ that causes membrane excitability. Depolarizes Vm moving closer to threshold.

If larger than 6. There is a reduction in neuron excitability. Depolarizes membrane and causes inactivation of V-gated Na+ channels

40
Q

How does hypokalemia influence neuron excitability

A

decrease of K+

reduces membrane excitability. Hyperpolarizes membrane further from threshold.

41
Q

How does hypercalcemia influence neuron excitability

A

If there is too many Ca2+ in ECF it will reduce membrane excitability.

42
Q

How does hypocalcemia influence neuron excitability

A

with not enough Ca2+ in the ECF it will increase membrane excitability

43
Q

Explain what the local current flow is during an AP

A

It is when a certain section of an axon is experiencing depolarization through V-gate Na+ channels opening and Na+ influxing in. Which will then cause depolarization of the next axon segment to reach threshold. The segment before beings to enter refractory period where K+ leaves the neuron.

44
Q

How does AP move along myelinated axons

A

AP jumps from node to node (saltatory conduction), this speeds up conduction velocity

45
Q

how can conduction of velocity of AP increase?

A
  • if axons have myelin

- or if axons have bigger diameter

46
Q

what are two demyelination diseases?

A

Guillain-barre syndrome (CNS)

Multiple Sclerosis (PNS)

47
Q

What is Multiple Sclerosis?

A

a demyelination disease. When myelin gets destroyed at the node of Ranvier. Since missing myelin a lot of Na+ will get out of the cell.

Physiology (6 decks)

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