Cumulative Exam Part 5

Question 1

Normal resting potential inside the plasma membrane

Answer 1

-70 mV

Question 2

Which way does K move according to the electrochemical gradient?

Answer 2

Out

Question 3

Which way does Ca move according to the electrochemical gradient?

Answer 3

Inside

Question 4

Pump that maintains resting potential and powered by ATP

Answer 4

Sodium potassium pump

Question 5

Sodium influx making the membrane potential more positive

Answer 5

Depolarization

Question 6

Potassium efflux making the membrane potential more negative

Answer 6

Repolarization

Question 7

More polarized than resting potential

Answer 7

Hyperpolarization

Question 8

How does sodium flow into the cell if the membrane is so impermeable to it?

Answer 8

Opening of specific membrane channels

Question 9

Variable strength electrical signals that travel over short distances and lose strength as they travel away from the source

Answer 9

Graded potential

Question 10

What causes a graded potential?

Answer 10

Opening and closing of gated channels

Question 11

Large uniform electric signals that can travel great distance without losing strength

Answer 11

Action potential

Question 12

Where do action potentials occur?

Answer 12

Axon

Question 13

Action potential is triggered or not; only occurs when threshold is reached

Answer 13

All or none

Question 14

What is the threshold level of voltage gated sodium channels

Answer 14

-60 to -55 mV

Question 15

What is the 1st step in producing an action potential?

Answer 15

Graded depolarization brings an area of excitable membrane to threshold

Question 16

What is the 2nd step in producing an action potential?

Answer 16

Activation of sodium channels causes rapid depolarization, Na+ rush into the cytoplasm, inner membrane changes from negative to positive

Question 17

What is the 3rd step in producing an action potential?

Answer 17

Closing of sodium gated channels, opening of potassium gated channels; repolarization

Question 18

What is the 4th step in producing an action potential?

Answer 18

Potassium channels close when membrane reaches resting potential, membrane is hyperpolarized to -90 mV and returns to resting potential

Question 19

Unmyelinated axons in propagation?

Answer 19

Continuous

Question 20

Myelinated axons in propagation?

Answer 20

Saltatory

Question 21

Neurotransmitters that cause hyperpolarization of postsynaptic membranes, suppress action potentials

Answer 21

Inhibitory

Question 22

Neurotransmitters that cause depolarization of postsynaptic membrane, promotes action potentials

Answer 22

Excitatory

Question 23

What does the effect of a neurotransmitter depend on ?

Answer 23

Receptor

Question 24

Any synapse that releases ACh

Answer 24

Cholinergic synapse