Exam 2 Powerpoint 7

Question 1

Reversal Potential

Answer 1

Point at which a move in potential in either direction will have opposing effects.

Question 2

Rule #1

Answer 2

Ions only move through open channels

Question 3

Rule #2

Answer 3

Ions only move to seek their equilibrium

Question 4

Rule #3

Answer 4

Ion movement causes a current that alters the neurons potential

Question 5

Hyperpolarize

Answer 5

+ charge exit or - charge enters

Question 6

Depolarize

Answer 6

+ charge enter or - charge leaves

Question 7

In a real neuron at rest, it is more permeable to

Answer 7

Potassium K+

Question 8

In a real neuron at AP, it is more permeable to

Answer 8

Sodium Na+

Question 9

Resting potential is mostly due to

Answer 9

K+, if it was entirely it would be exactly equilibrium potential

Question 10

Each ion pushes membrane towards its..

Answer 10

reversal potential

Question 11

Strength of ion push depends on

Answer 11

permeability, # of channels open

Question 12

Goldman equation

Answer 12

P(K out)+P(Na out)+P(Cl in)/
P(K in)+ P(Na in)+P(Cl out)

58 x Log(^)

Question 13

At rest:
PK:PNa=
PK:PCl=

Answer 13

1:0.03
1:0.1

Question 14

During AP:
PK:PNa=
PK:PCl=

Answer 14

1:15
1:0.1

Question 15

What happens to the resting membrane potential if we change the outside K+ concentration?

Answer 15

Higher: more +
Lower: more -

Question 16

What is responsible for the resting membrane potential?

Answer 16

K+

Question 17

At rest, Cl and Na have________ permeability

Answer 17

Small

Question 18

Most cells, not just neurons have a membrane potential that is generally______

Answer 18

Negative

Question 19

Muscle cells are more permeable to _____than other neurons so _____is more important than
____ for the resting membrane potential.

Answer 19

Cl Cl K

Question 20

What happens to the
action potential if we change the
outside Na+ concentration?

Answer 20

High, high
Low, low

Question 21

At rest, neuronal membranes more permeable to___ than___

Answer 21

K+ Na+

Question 22

At AP, neuronal membranes more permeable to___ than___

Answer 22

Na+ K+

Question 23

During repolarization, K+ ____ permeable than Na+

Answer 23

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