Brainscape's Knowledge GenomeTM

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


See full index

PS1060 - Intro to Biological Psychology > 3. Principles of Neural Transmission > Flashcards

3. Principles of Neural Transmission Flashcards

You may prefer our related Brainscape-certified flashcards:
Psychology 101 flashcards GRE® Psychology flashcards AP® Psychology flashcards
1
Q

What are the 3 types of neuron?

A

Multipolar (standard), Bipolar and Unipolar

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

Define a multipolar neuron

A

Many dendrites, one axon

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

Define a bipolar neuron

A

One dendrite at one end and one axon at the other

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

Define a unipolar neuron

A

One branch leaves the cell body and spreads in 2 directions

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

What is are all neurons common function?

A

Receive, process, transmit and output info

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

What are the common structures of the neuron?

A

Dendrites, cell body, axon hillock, axon, axon terminals and myelin sheath

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

What is the axon hillock?

A

The attachment from the cell body to the axon - determines if the signal will go any further down the axon (if the transmission is strong enough)

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

A nucleus within an atom consists of…

A

Protons and neutrons

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

What orbits the nucleus in an atom?

A

Electrons

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

Atoms are held together by what type of force?

A

Electrostatic force (opposites attract)

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

What are ions?

A

Atoms that have lost or gained one or more electrons

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

What are cations?

A

Positively charged ions

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

What are anions?

A

Negatively charged ions

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

Salts are made of what?

A

Ion

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

Why are salts able to dissolve?

A

Because the ions are able to separate and move freely

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

What are the 3 cations crucial for neural signalling?

A

Sodium, Potassium and Calcium

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

What does sodium do?

A

Generating action potentials

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

What does potassium do?

A

Maintains resting potential

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

What is calcium responsible for?

A

Synaptic transmission

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

What are the 2 anions involved in neural signalling?

A

Chloride ions and proteins

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

What do chloride ions do?

A

Suppress action potentials

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

What do proteins do?

A

Maintaining resting potential

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

Where is sodium found in the body?

A

Everywhere, mainly outside neurons (extracellular)

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

Where is potassium found?

A

Mainly inside neurons (intracellular)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where is calcium found?

A

Almost exclusively extracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Are chloride ions intra/extracellular?

A

Mostly extracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Are proteins intra/extracellular?

A

Mostly intracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define diffusion

A

The movement of particles from regions of high concentration to low concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is diffusion caused by?

A

The random movement of particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The speed of diffusion depends on what?

A

Temp, size of particles and how difficult it is for particles to travel through the liquid (viscosity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Define fully permeable

A

Allows all particles through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Define semi/selectively permeable

A

Only allows certain particles through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Neuronal cell membranes contain ‘pores’ made up of large proteins that allow certain ions to pass through, these are called…

A

Ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Ion channels are specific to how many ions?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Very large proteins are usually up of several identical parts, which are called what?

A

Subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Ion channels are made up of ___ ___ that come together and are held together by their shape

A

Smaller proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are ion channels critical for?

A

For cells to communicate with the ‘outside’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Neurons have an electrical potential across their membranes, this potential is a result of:

A
  1. Differences in ionic concentrations between the inside and outside of the neuron
  2. Ion channels in the neuronal cell membrane that only allow certain ions to pass in and out of the neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How can the membrane potential be measured?

A

Using tiny electrodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Define an electrical potential

A

The strength of the electric field which surrounds charged particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

When neurons are at ‘rest’, the charge is what?

A

Slightly more negative than the outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The slightly negative potential is known as…?

A

The resting membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the resting potential in volts?

A

Approx -70 millivolts (mV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What type of permeability does the cell membrane have?

A

Semipermeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Which ion channels are usually closed?

A

All of them apart from potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

When neurons are at rest, which ions can still freely move across the cell membrane?

A

The potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Due to the concentration of potassium ions being higher inside the cell than outside, what happens?

A

Some of the potassium ions leave the cell by diffusion

48
Q

Because potassium ions are the only ones which can move freely, what does this mean for the charge of the neuron?

A

It is slightly more negative as the positive potassium ions continue to leave

49
Q

What are the 2 opposing forces that determines the resting potential?

A
  1. Concentration difference

2. Electrostatic force

50
Q

Describe how the concentration difference determines the resting potential

A

It drives potassium out of the cell making the inside more negative (because there is a lower concentration of K outside the cell)

51
Q

Describe how the electrostatic force determines the resting potential

A

Because opposites attract, potassium is drawn back into the negative inside of the cell

52
Q

When the two forces are balanced, an equal number of K ions leave and enter the cell, this is called ___

A

The equilibrium potential (the resting potential)

53
Q

When the concentration is balanced, why is there a slightly negative resting potential?

A

Because there are more proteins than potassium in the cell

54
Q

Why is there more potassium inside the cell in the first place?

A

Because of the sodium-potassium pump

55
Q

What is the sodium-potassium pump?

A

An ion channel that pumps sodium out of the cell and potassium into the cell

56
Q

Why does the sodium-potassium pump require energy?

A

Because it works against the concentration gradient

57
Q

Where does the sodium-potassium pump get energy from?

A

ATP

58
Q

What quantity of sodium and potassium gets pushed in/out of the cell by the Na/K pump?

A

The Na/K pumps 3 Na out for every 2 K in

59
Q

Define hyperpolarization

A

Increase in resting potential (making the membrane more negative)

60
Q

Define depolarization

A

Decrease in resting potential (making the membrane less negative)

61
Q

The membrane potential is the sum of…

A

The depolarization and hyperpolarization

62
Q

What causes an action potential (AP) to occur?

A

If depolarisation exceeds a threshold

63
Q

Describe the 3 main features of an AP

A
  1. Sudden & brief (1-2ms)
  2. Momentarily reverse the membrane potential (from -70mV to +40mV)
  3. Repolarizes quickly (back to normal)
64
Q

What determines the intensity of AP’s?

A

The frequency that they occur

65
Q

AP’s rely on which type of ion channels, what are they called?

A

Voltage-gated ion channels

66
Q

What are voltage gated ion channels?

A

A complex cascade of opening and closing voltage-gated ion channels that govern the influx and outflow of Na and K ions

67
Q

The voltage-gated channels are ___ at resting potential?

A

Closed

68
Q

If you pass a current into the cell, the membrane begins to…

A

Depolarise (becomes less negative)

69
Q

The channels begin to open when the membrane is…

A

Depolarised

70
Q

What is the threshold for the voltage-gated channels to open?

A

-40mV

71
Q

When the voltage gated channels, which ions diffuse from outside the cell to inside the cell as a result of the concentration gradient?

A

Sodium ions

72
Q

When the sodium ions enter the cell, this further depolarises the cell which causes what to happen?

A

More channels to open

73
Q

The increase in membrane potential goes from -70mV to what?

A

+40mV

74
Q

Once the concentration of Na is balanced by the electrostatic forces, the voltage-gated channels become…

A

‘Inactivated’

75
Q

What does it mean for the voltage-gated channel to be inactivated?

A

The channel will stop allowing sodium into the cell

76
Q

At what voltage will the potassium channels open?

A

+30mV

77
Q

When the potassium channels open, potassium will begin to leave the cell until when?

A

Until the potential reaches its resting potential again

78
Q

When the original resting potential is reached, what happens to the sodium channels?

A

They return to their original closed state

79
Q

Voltage-gated channels have a sensor ‘paddle’, describe this ‘paddle’

A

It is a protein structure which changes shape depending on membrane potential

80
Q

When the ‘paddle’ changes shape, what happens in the voltage-gated channel?

A

They will open or close

81
Q

What causes the ‘paddle’ to change shape?

A

The ‘paddles’ are pulled away/into the cell depending on the membrane potential - as a result of electrostatic forces

82
Q

Describe the process of how the cell returns to its resting potential

A

When the Na channels close and become inactivated, the voltage-gated K channels open so that no more Na ions can enter by K ions begin to diffuse into the cell. This causes the membrane potential to become negative again

83
Q

Why does the membrane potential briefly become hyper polarised?

A

Due to the K ions leaving the cell as a result of the concentration gradient

84
Q

What is the refractory period?

A

The period immediately after an AP during which another AP cannot be elicited, due to the inactivation of the voltage-gated Na channels which remain inactive for a period of time long enough for the AP to move on

85
Q

If an AP depolarises the neighbouring membrane region beyond the threshold, what will occur?

A

An AP in the neighbouring region and so on

86
Q

What is the reason that AP’s can only spread in one direction?

A

Due to the refractory period

87
Q

When the Na channels become inactivated they will remain closed regardless of membrane potential, what does this prevent?

A

Another AP from occurring

88
Q

In the time that the channels are inactivated, where does the AP go?

A

It moves away from this area and therefore in one direction only

89
Q

There is exposed membrane between the myelin sheath, what is this called?

A

Ranvier

90
Q

Due to a myelinated axon, what does this mean in terms of the Ranvier nodes?

A

That ion flow only occurs at these nodes

91
Q

Impulses leap from node to node, what is this called?

A

Saltatory conduction

92
Q

What does it mean for a disease to be demyelinating?

A

It breaks down the myelin sheath

93
Q

What does a demyelinating disease prevent?

A

Saltatory conduction

94
Q

Why is fugu so toxic?

A

Because they contain tetrodotoxin

95
Q

What does tetrodotoxin do?

A

Blocks the opening of voltage-gated Na channels and therefore APs cannot be generated

96
Q

How do local anaesthetics work (what do they block)?

A

They block voltage-gated Na channels and therefore APs cannot be generated to signal pain to the brain

97
Q

APs are transmitted from one neurone to another at synapses, what is the gap called?

A

The synaptic cleft

98
Q

What are the 2 ways which signals can be transmitted across the synaptic cleft?

A

Chemically and electrically

99
Q

Describe the 5 features of an electrical synapse

A
  1. Large channels which connect one cell to another
  2. Direct connection between two neurons
  3. Rely on special channel proteins - gap junctions
  4. Allows small molecules and ions to flow between cells
  5. Allow APs to pass from one neurone to the next
100
Q

What are the special channel proteins in an electrical synapse called?

A

Connexin

101
Q

Outline the 6 steps of how a chemical synapse works?

A
  1. AP arrives at the presynaptic membrane
  2. Voltage gated Ca2+ channels open, allowing Ca2+ into the cell
  3. Synaptic vesicles fuse with membrane and then rupture which releases neurotransmitter molecules
  4. Transmitter binds to postsynaptic receptors, opening ion channels
  5. If the channel is for Na+ - depolarisation occurs (EPSP)
  6. If channel is for CL - hyper polarisation occurs (IPSP)
  7. EPSP?IPSP propagated along membrane
102
Q

What is an EPSP?

A

Excitatory postsynaptic potential

103
Q

What is an IPSP?

A

Inhibitory postsynaptic potential

104
Q

What are receptors?

A

Membrane proteins that bind neurotransmitters

105
Q

Describe the lock and key principle

A

That each receptor type can only bind to a specific neurotransmitter

106
Q

When a transmitter molecule binds to the receptor, how does it cause an ion channel to open?

A

By causing the receptor to change shape

107
Q

What are the 2 types of receptor?

A

Ionotropic receptors and Metabotropic receptors

108
Q

Define ionotropic receptors

A

The receptor itself is an ion channel (fast)

109
Q

Define metabotropic receptors

A

The receptor causes a separate ion channel using G-protein coupling (slow)

110
Q

When the ion channel is opened by the postsynaptic receptor, what does this result in?

A

Either depolarisation or hyperpolarisation

111
Q

EPSPs and IPSPs will spread towards what in the postsynaptic neurone?

A

The axon hillock

112
Q

Once the EPSPs/IPSPs reach the axon hillock, what determines whether an AP is elicited?

A

If the sum of the EPSPs/IPSPs reaches the threshold or not

113
Q

If the sum of EPSPs/IPSPs reaches the threshold, what happens next?

A

The AP is elicited and travels along the axon to the axon terminal which causes release of neurotransmitter

114
Q

EPSPs/IPSPs from different synapses can sum in __ and __

A

Time and space

115
Q

Define spatial summation

A

Many axons converge on one neurone

116
Q

Define temporal summation

A

Many EPSPs/IPSPs occur at the same time

PS1060 - Intro to Biological Psychology (10 decks)

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