05 Action Potential, synapses & transmitters Flashcards Preview

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Flashcards in 05 Action Potential, synapses & transmitters Deck (56)
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1
Q

031: What is the main difference between Ionotropic receptors and Metabotropic receptors?

A

Metabotropic receptors have a cascade of events that take time to build up but they are going to be more wide spread and last a lot longer.

2
Q

032: What is a SSRI?

A

An antidepressant that helps prolong the synapse of serotonins.

3
Q

033: _____ is an antagonist that binds to acetylcholine receptors on skeletal muscle and paralyzes them so that they can’t contract.

A

Curare

4
Q

034: _____ means there is a little packet of neurotransmitters containing 10,000 molecules that get released from the synaptic vesicle.

A

Quanta

5
Q

035: What happens when you have a large burst of action potential?

A

You will begin to release a lot of packets of neurotransmitters and you will see that the depolarization effects of that neurotransmitter on the post-synaptic cell will linger for a longer period of time.

6
Q

037: _____ have a particularly good effect at shunting and keeping the cell from getting too over excited.

A

IPSP

7
Q

038: T/F G-protein second messenger signals are fast and cannot be amplified.

A

False. They are slow but get amplified.

8
Q

039: Transmitter signals can _____ and _____.

A

converge, diverge

9
Q

033: What is an example of a receptor agonist?

A

Nicotine

10
Q

021: T/F Gap Junctions are selective and allow ions to pass between cells directly.

A

False. Gap Junctions do allow ions to pass between cells directly, but they are NOT considered to be selective because they are big enough that virtually any ion can pass through.

11
Q

021: T/F Gap Junctions are found mostly in sensory and motor neurons, but are relatively rare in adult neurons.

A

True

12
Q

022: Most communication in your brain occurs via ________?

A

Synapses

13
Q

022: The gap between the pre and post synaptic cells is known as the ___________ and is how many nanometers wide?

A

Synaptic Cleft, 15-20 nanometers wide.

14
Q

022: What is the difference between synaptic vesicles and granules?

A

Synaptic vesicles contain NEUROTRANSMITTERS, while granules contain PEPTIDES.

15
Q

022: T/F Neurotransmitters can be inhibitory or excitatory.

A

True

16
Q

023: Asymmetrical synapses are also known as Type ___ synapses.

A

Type I

17
Q

023: Most synapses on the cell body (soma) are _________, keeping the cell from becoming too depolarized and preventing it from firing all of the time.

A

Inhibitory

18
Q

024: What are synapses in the peripheral nervous system called?

A

Neuromuscular Junctions (NMJ)

19
Q

025: Dendritic _______ compartmentalize signals, improve communication between cells and become the site of the synapse.

A

Spines

20
Q

025: T/F Dendritic spines can grow within a matter of seconds to minutes, and can come and go.

A

True

21
Q

026: A ________ is a molecule that can bind to a neurotransmitter receptor, but itself is not a neurotransmitter. Opiates are an example of this.

A

Ligand

22
Q

026: What are the three major categories of neurotransmitters?

A

Amino acids, Amines, and Peptides.

23
Q

026: Acetylcholine (Ach), Dopamine, Epinephrine, and Norepinephrine are classified under which category of neurotransmitter?

A

Amines. (These were the first neurotransmitters to be discovered!)

24
Q

027: Where are neurotransmitters synthesized?

A

ROUGH Endoplasmic Reticulum (ER)

25
Q

029: T/F Autoreceptors are on the presynaptic cell and shut down the release of neurotransmitters.

A

True

26
Q

028: The process in which neurotransmitters are released is called ________, while the refilling of the vesicle is called ________.

A

Exocytosis, Endocytosis

27
Q

028: What are Lewy Bodies?

A

Abnormal aggregates of protein (plaques) that are commonly associated with dementia and Parkinson’s Disease.

28
Q

029: T/F Autoreceptors are on the Presynaptic cell and shut down the release of neurotransmitters.

A

True

29
Q

030: ________ receptors open ion channels and are not very selective.

A

Ionotropic

30
Q

002: What are action potentials?

A

Action potentials are a rapid reversal of a neuron’s membrane potential.

31
Q

002: Inside of the cell is more _____________ relative to the outside of the cell.

A

Hyperpolarized.

32
Q

002: Where do action potentials occur?

A

In axons, right at the axon hillock.

33
Q

002: How long does it take for a cell to depolarize?

A

1-2 msec.

34
Q

002: What are some ways in which an action potential can be triggered?

A

Buildup of currents, stretch receptor can trigger an action potential, changes in temperature, etc.

35
Q

002: What period is responsible for the action potential moving in one direction?

A

Refractory period.

36
Q

003: What channel initiates the action potential?

A

Electrically gated sodium ion channel.

37
Q

003: Membrane potential must increase above a __________ to cause an action potential.

A

Threshold.

38
Q

004: What carries the code for a cell to depolarize a particular size during an action potential?

A

The firing rate, or firing frequency.

39
Q

005: What two channels are most predominant in the action potential?

A

The sodium and potassium channels.

40
Q

006: During resting state, membrane potentials is about ____.

A

-70 mV.

41
Q

006: During resting state, K channels are _______, Na channels are ________.

A

Open, closed.

42
Q

007: During depolarization, K channels are _______, Na channels are ________.

A

Open, open.

43
Q

007: What depolarizes the cell and in what direction?

A

Sodium, moving inside the cell.

44
Q

008: During repolarization, K channels are _______, Na channels are ________.

A

Open, closed.

45
Q

008: What repolarizes the cell and in what direction?

A

Potassium, moving outside the cell.

46
Q

009: T/F: Sodium balance restores resting potential.

A

False, potassium.

47
Q

010: What is the difference between the potassium equilibrium and sodium equilibrium?

A

Sodium equilibrium: changes rapidly, initiates action potential, conductance changes very quickly, and closing very quickly.

Potassium equilibrium: trials behind sodium equilibrium by a msec, responds more slowly, gradually helps to return to balance.

48
Q

011: How long do voltage-gated Na+ channels remain open?

A

About 1 millisecond (ms) because the globule quickly blocks the pore and causes it to last this long.

49
Q

012: Voltage-gated Na+ channels respond slower than K+ channels. T/F?

A

FALSE, Voltage-Gated K+ channels respond slower because they have to wait until a structural change occurs in the channel.

50
Q

013: During the refractory period, what two events take place?

A

BOTH Na+ and K+ channels stay closed and the Na+/K+ pump helps restore balance.

51
Q

014: Neurons use the redistribution to convey information. T/F?

A

TRUE because changes in depolarization causes the current to spread toward the soma and eventually, the axon hillock.

52
Q

015: How fast can an action potential travel?

A

Average of 10 meters per second (varies with diameter of axon).

53
Q

016: Myelinated fiber tracts conduct ______________ signals.

A

Faster.

54
Q

017: At the Nodes of Ranvier, there are __________.

A

Channels that open and close.

55
Q

018: __________ cells send out a consistent high frequency burst while _____________ cells start with a burst and settle into a rhythmic pattern.

A

Stellate, Parametal.

56
Q

020: Otto Loewi showed what with his experiment on frog hearts?

A

That synaptic transmission was causing the release of something from the vagus nerve and in that solution was the chemical (Acetylcholine) causing the heart to slow down.