Action Potential and Synapse

Question 2

Resting membrane potential (-70mV) is closest to the Nernst potential for…

Answer 2

potassium (due to the large number of potassium channels)

Question 3

What is the voltage of resting membrane potential?

Answer 3

-70mV

Question 4

What is the voltage of threshold?

Answer 4

-55mV

Question 5

Resting membrane potential is re-established or maintained by the…

Answer 5

Na+/K+ ATPase pump

Question 6

What occurs during the rising phase of an action potential?

Answer 6

Depolarization increases voltage of membrane by allowing sodium in

Question 7

What occurs during the falling phase of an action potential?

Answer 7

Repolarization decreases voltage of membrane by allowing potassium out

Question 8

After the refractory period, what is the voltage of the membrane?

Answer 8

-70mV or resting state

Question 9

Allowing sodium in leads to…

Answer 9

Depolarization increasing voltage of membrane

Question 10

Allowing potassium out leads to…

Answer 10

Repolarization decreasing voltage of membrane

Question 11

Resting membrane potential is closest to which Nernst potential? Why?

Answer 11

Potassium due to large number of potassium channels.

Question 12

presynaptic terminal events

First, action potential stimulates what to open?

Answer 12

Voltage activated calcium channels

Question 13

presynaptic terminal events

Influx of calcium into the neuron causes…

Answer 13

release of neurotransmitter by regulated exocytosis

Question 14

What are the types of post synaptic receptors?

Answer 14

1. Ligand gated ion channels
2. Metabotropic, second messenger

Question 15

Metabotropic, second messenger post synaptic receptors are 75% what?

Answer 15

G reactive proteins

Question 16

Function of excitatory ligand gated ion channels

Answer 16

Either calcium or sodium enter post synaptic cell

Question 17

Function of inhibitory gated ion channels

Answer 17

Either potassium leaves or chloride enters post synaptic cell

Question 18

Functions of metabotropic, second messenger post synaptic receptors

Answer 18

1. Open channel
2. Activate either adenyl cyclase or guanyl cyclase
3. Activate enzymes
4. Activate gene transcription

Question 19

What are four characteristics of synapses?

Answer 19

1. Fatigue
2. Post-tetanic facilitation
3. Synaptic delay
4. Summation

Question 20

What is post-tetanic facilitation?

Answer 20

Increase in calcium in presynaptic terminal

Question 21

What type of summation are there?

Answer 21

Temporal and spatial

Question 22

What does summation impact?

Answer 22

Increases the frequency of firing