Brainscape's Knowledge GenomeTM

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


See full index

MCAT Biology > The Nervous System > Flashcards

The Nervous System Flashcards

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

What is the soma in a neuron? What does it contain?

A

Cell body

Nucleus, ER, and ribosomes

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

What is a collection of cell bodies called in the CNS?

A

Nucleus

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

What is a collection of cell bodies called in the PNS?

A

Ganglion

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

What is the role of astrocytes? 3

A
  1. Nourish neurons
  2. Form the blood/brain barrier
  3. Perform the scarring process in the CNS, which reduces the potential for neural regrowth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of ependymal cells?

A

Produce cerebrospinal fluid

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

What is the role of oligodendrocytes?

A

Produce myelin in CNS

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

What is the role of Scwann cells?

A

Produce myelin in PNS

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

During the action potential, which ion channel opens first?

A

Na+

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

What is the voltage of the resting membrane potential?

A

-70mV

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

What enzyme maintains the resting membrane potential?

A

Na+/K+ ATPase

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

What is the threshold for the first ion channel to open?

A

-50mV

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

What regulates the Na+ channel to close?

A

Full depolarization at +35mV

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

During the action potential, which ion channel opens second?

A

The K+ channel

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

At what voltage does the second channel open?

A

+35mV

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

What regulates the K+ channel to close?

A

Hyperpolarization to slightly below -70mV

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

What is the absolute refractory period?

A

When the axon is GETTING depolarizaed and getting hyperpolarized: the cell is unable to fire another action potential –> whenever Na+ and K+ ion channels are open –> think of the bell on the curve, until -70

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

What is the relative refractory period?

A

When the axon requires a larger than normal stimulus to fire an action potential: from hyperpolarization to resting potential

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

What are the Nodes of Ranvier?

A

Exposed areas of demyelinated axons

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

What are the parts of the synapse?

A
  1. Synaptic bouton of one neuron
  2. Synaptic cleft
  3. Membrane of post-synaptic cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the speed of the impulse down the axon depend on? 2 things
Which effect is more significant?

A
  1. Length: decrease length = increase conduction

2. Cross-sectional area: increase = increase conduction –> more significant

21
Q

Which neurons have very little myelin?

A

Sensory neurons

22
Q

What do local anesthetics inhibit?

A

The Na+ ion channel

23
Q

What ion channel opens once the impulse has reached the synaptic bouton? Where do these ions go?

A

Ca+, come inside the cell

24
Q

What is white matter?

A

Myelinated axons

25
Q

What is grey matter?

A

Unmyelinated cell body and dendrites

26
Q

What is the difference between monosynaptic and polysynaptic reflexes?

A

The use of interneurons

27
Q

What is the equation to calculate a membrane potential based on the concentrations of only 1 ion?

A

Nernst:

E = 61.5/z(charge of ion) x log [ion out] / [ion in]

28
Q

What is the equation to calculate a membrane potential based on the concentrations of multiple ions?

A

Goldman-Hodgkin-Katz:
Vm = 61.5 x log (Pion1.[ion out] + Pion2.[ion out]) / (Pion1.[ion in] + Pion2.[ion in])
P = permeability
BUT: invert denominator for ions with a different charge

29
Q

Which one is the presynaptic neuron?

A

The one releasing the NTs

30
Q

Which one is the postsynaptic neuron?

A

The one receiving the NTs

31
Q

Why do the concentrations of K+ ions play a much larger role than the Na+ concentrations in determining the membrane potential?

A

Because K+ has a higher permeability than Na+

32
Q

What neuron type is responsible for pilo erection? Sensory or motor?

A

Motor

33
Q

Inside the cell, are there more Na+ or K+ ions?

A

K +

34
Q

What is the normal movement of ions to maintain the resting membrane potential?

A

3 Na+ ions move out for every 2 K+ ions moved in

35
Q

Outside the cell, are there more Na+ or K+ ions?

A

Na+

36
Q

Inside the cell: negative or positive?

A

Negative

37
Q

Outside the cell: negative or positive?

A

Positive

38
Q

What are the 3 statuses for the Na+ ion channel?

A

Open, closed, or inactivated

39
Q

When does inactivation of Na+ channels occur? What is the purpose?

A

When the membrane potential is 35, this is the fast closing of the gate, the other one is slow

40
Q

What is the status of the Na+ channel for another action potential to be fired?

A

Closed

41
Q

What does a higher magnitude action potential change?

A

The frequency of the action potential

42
Q

Are the Na+ ions going in or out?

A

In

43
Q

Are the K+ ions going in or out?

A

Out

44
Q

When K+ blood concentration is low, how will this affect the action potential?

A

When the K+ blood concentration is low, the drive for the K+ ion to leave the cell is high, which means the membrane potential will reach even lower values during hyperpolarization = will rneed a higher stimulus for an action potential to happen

45
Q

When K+ blood concentration is high, how will this affect the action potential?

A

The neuron will be more excitable because the resting membrane potential will be higher

46
Q

What happens on the axon at the unmyelinated portions?

A

+ charges flow down and open Na+ channels as they go –> recharging

47
Q

Does the Ca2+ go in or out at the axon terminal?

A

In the cell!

48
Q

How to calculate the change in electric potential energy of an ion crossing the membrane?

A

U = Delta V . q

Delta V = difference between outside (0V) and inside (-70mV)
q = charge of the ion: each charge = 1.6 x 10^-19 C

MCAT Biology (18 decks)

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