Action Potentials & Signaling

Question 1

This is where an action potential is transmitted from a neuron to another cell

Answer 1

Synapse

Question 2

This is the cell releasing the neurotransmitter/signal

Answer 2

pre-synaptic cell

Question 3

This is the cell receiving the neurotransmitter/signal

Answer 3

post-synaptic cell

Question 4

What type of synapse uses neurotransmitter to communicate between cells?

Answer 4

chemical synapse

Question 5

What is the small space between cells in a chemical synapse?

Answer 5

Synaptic cleft

Question 6

True or false: an action potential will always propagate to the post-synaptic cell

Answer 6

False. The graded potential may not be strong enough to propagate AP in post-synapse

Question 7

propagation of AP in the post-synaptic cell is dependent on:

Answer 7

type of chemically gated channel associated with neurotransmitter, amount of neurotransmitter released, sensitivity of post-synaptic cell

Question 8

This type of synapse directly connects cells through a gap junction

Answer 8

electrical synapse

Question 9

This lasts about 0.2-0.5msec

Answer 9

Synaptic delay-time it takes for neurotransmitter to cross synaptic cleft and trigger Ca2+ influx

Question 10

True or false: more synapses means faster signal transfer

Answer 10

false. more synapses increases overall synaptic delay.

Question 11

These are the chemical signals that bind to chemically gated channels on the post-synaptic cell

Answer 11

Neurotransmitters

Question 12

True or false: the type of neurotransmitter determines the response in the post-synaptic cell

Answer 12

False. The type of channel the neurotransmitter binds to determines the response.

Question 13

What stops neurotransmitter action?

Answer 13

Diffusion away from the synaptic cleft, breakdown by enzyme & re-uptake into synaptic vesicle

Question 14

Excitatory effects do what?

Answer 14

cause depolarization of post-synaptic membrane and promote action potentials

Question 15

Inhibitory effects do what?

Answer 15

cause hyperpolarization of post-synaptic membrane and suppress action potentials

Question 16

This is what happens when one neuron sends the same signal over and over

Answer 16

Temporal summation

Question 17

This is what happens when multiple signals are sent by multiple neurons simultaneously

Answer 17

spatial summation

Question 18

True or false: all signals received during spatial summation are the same

Answer 18

False. some signals may be inhibitory while others are excitatory

Question 19

If a signal opens many potassium channels, it is inhibitory (IPSP) or excitatory (EPSP)?

Answer 19

IPSP

Question 20

Do action potentials ever die out?

Answer 20

No, they continue until there are no more voltage gated channels. One will trigger the next indefinitely

Question 21

Can a graded potential eventually die out?

Answer 21

Yes, it will get weaker and weaker the further it travels