Brainscape's Knowledge GenomeTM

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


See full index

Physl > Nervous System 3 - Synaptic Transmission > Flashcards

Nervous System 3 - Synaptic Transmission Flashcards

1
Q

What are the sequence of events involved in transmission at a typical chemical synapse?

A
  • An action potential invades the presynaptic terminal
  • Depolarization of the terminal causes opening of voltage gated Ca2+ channels
  • Ca2+ enters through channels
  • Ca2+ causes vesicles to fuse with the presynaptic membrane
  • Transmitter is released into synaptic cleft via exocytosis
  • Transmitter binds to receptor molecules in the postsynaptic membrane
  • Transmitter binds to receptor molecules in the postsynaptic membrane
  • Opening or closing of postsynaptic channels
  • Postsynaptic current causes excitatory or inhibitory postsynaptic potential that changes the excitability of the postsynaptic cell
  • Removal of neurotransmitter by glial uptake or enzymatic degradation
  • Retrieval of vesicula membrane from plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens when an Action Potential invades the Presynaptic terminal?

A

It causes openings of voltage gated Ca2+ channels

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

What does the opening of Voltage gated Ca2+ channels allow for?

A

The movement of Calcium inside of the cell

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

What does the influx of Calcium trigger?

A

It triggers vesicles containing transmitters to fuse with the presynaptic membrane

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

What happens after vesicles fuse with the presynaptic membran?

A

The transmitter is released in the cleft via exocytosis

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

What happens after transmitters are released from the vesicles?

A

The transmitters bind to receptor molecules in the postsynaptic membrane

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

What happens after transmitters bind to to receptor molecules of the postsynaptic membrane?

A

It causes opening or closing of the postsynaptic channels which cause excitatory or inhibitory postsynaptic potential that changes the excitability of the postsynaptic cell

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

How are neurotransmitter removed?

A

By glial uptake or enzymatic degradation

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

What is the main excitatory transmitter?

A

Glutamate

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

What does Glutamate cause?

A

Sodium channels to open allowing sodium to enter the cell

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

What is the main inhibitory neurotransmitter?

A

GABA

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

What does GABA cause?

A

Cl- channels allowing Cl- to enter the cell causing hyperpolarization

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

What happens to the EPSP when Calcium channels are blocked in the presynaptic neuron?

A

No EPSP occurs

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

What does Calcium Chelator do?

A

It binds to calcium inside a nerve terminal preventing calcium from triggering transmitter release and therefore blocking postsynaptic potentials

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

What is an Endplate?

A

The synapse between nerve and muscle (neuromuscular junction)

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

What is an End-Plate potential?

A

An EPSP at the neuromuscular junction

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

What does EPSP stand for?

A

Excitatory postsynaptic potential

18
Q

How does distance affect EPSPs?

A

EPSP decay in size over long distances

19
Q

What does MEPP stand for?

A

Miniature endplate potential

20
Q

What does a MEPP result from?

A

The release of a very small amount of neurotransmitter contained in a single vesicle

21
Q

What causes a single vesicle to be released?

A

Sometimes due to an action potential and sometimes released spontaneously

22
Q

How do we know that transmitters are released in quantal packets?

A

Because each packet results in the same amount of depolarization which is a MEPP

23
Q

How much depolarization will the smallest Quantum produce?

A

0.4mV of depolarization

24
Q

What is a Synaptic delay?

A

The time between onset of presynaptic spike and onset of EPSP

25
Q

What is the neurotransmitter at the neuromuscular junction?

A

Acetylcholine (ACh)

26
Q

What does ACh cause?

A

It opens channels that conduct both Na+ and K+ ions

27
Q

What does AChE break down?

A

ACh for recycling

28
Q

What happens once ACh binds to receptors?

A

Receptors at the NMJ open to allow sodium to enter and potassium to leave

29
Q

What is an example of Transmitter and Voltage gated channels working together?

A

In the NMJ ACh opens channels that allow sodium to enter and K+ to leave and then voltage gated Na+ channels allow sodium to enter both working to bring the postsynaptic cell to threshold

30
Q

What occurs in Myasthenia gravis?

A

The loss of voltage gated Ca2+ channels in presynaptic terminals of motor neurons which results in reduced neurotransmitter release at NMJ and muscle weakness

31
Q

What occurs in Botulism?

A

Food poisoning from clostridium bacteria which impairs transmitter release at NMJ causing paralysis of muscle

32
Q

What is the Reversal Potential?

A

The membrane potential at which there is zero net current through a transmitter gated channel because ions are flowing in and out

33
Q

Which channel conducts sodium and potassium?

A

ACh receptor channels

34
Q

What does the Reversal Potential depend on?

A

It depends on the relative conductances of the synaptic channel to ions and also on the equilibrium potentials for these ions

35
Q

What is the rule surrounding membrane potentials and reversal potentials?

A

Vm will always move towards the reversal potential of the synaptic channel when its conductance increases (when the channel opens)

36
Q

What is the difference between Na and K transmission in between ACtion Potential and EPSPs at NMJs?

A

In Action potentials have separate Na and K channels

In EPSPs acetylcholine channels conduct both Na and K

37
Q

What is the Erev in EPSP?

A

0 mV

38
Q

What are EPSPs at NMJs triggered by?

A

Acetylcholine

39
Q

What are action potentials initiated by?

A

Depolarization

40
Q

What are channels controlled by in EPSPs?

A

Transmitters; they are not sensitive to voltage

41
Q

What are EPSPs blocked by?

A

Curare

Physl (94 decks)

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