Resting and Action Potentials

Question 1

What is referred to as the charge difference from inside the cell membrane vs. outside?

Answer 1

membrane potential

Question 2

What equation calculates the equilibrium potential?

Answer 2

Nernst Equation

Question 3

What is the equilibrium potential of Cl-?

Answer 3

-70mV

Question 4

What is the equilibrium potential of K+?

Answer 4

-90mV

Question 5

What is the equilibrium potential of Na+?

Answer 5

+60mV

Question 6

What is the equilibrium potential of Ca2+?

Answer 6

+130mV

Question 7

Does K+ want to go into or out of the cell at resting potential?

Answer 7

K+ wants to leave until inside of cell -90mV.

Question 8

This mechanism is responsible for pumping 3 Na+ OUT of the cell while pumping 2 K+ INTO the cell.

Answer 8

Na+/ K+ pump (ATPase)

Question 9

What ion is the MAIN factor in RMP?

Answer 9

K+

Question 10

During hyperkalemia, does the inside of the cells become more negative or less negative?

Answer 10

less negative

Question 11

During hypokalemia, does the inside of the cells become more negative or less negative?

Answer 11

more negative

Question 12

At rest, is there more K+ inside or outside the cell?

Answer 12

inside

Question 13

At rest, is there more Na+ inside or outside the cell?

Answer 13

outside

Question 14

What is the gap between neurons where signals are passed to one another?

Answer 14

synapse

Question 15

Do synapses use chemical or electrical stimuli to pass information?

Answer 15

both

Question 16

True or false- synapses can NOT be both inhibitory and excitatory

Answer 16

false, they can be both depending on the signal/ neurotransmitter

Question 17

This occurs when positive Na+ ions rush into the cell, making it less negative

Answer 17

depolarization

Question 18

_______ potentials weaken over distance from the source

Answer 18

graded

Question 19

This type of signal is caused by an influx of Na+, promoting depolarization

Answer 19

excitatory

Question 20

This type of signal is caused by the opening of Cl- channels

Answer 20

inhibatory

Question 21

What ion is primarily responsible for depolarization

Answer 21

Na+ rushing in

Question 22

What ion is primarily responsible for repolarization?

Answer 22

K+ flooding out

Question 23

What ion is primarily responsible for hyperpolarization?

Answer 23

influx of K+ flooding out

Question 24

This type of gated ion channel opens or closes in response to small voltage changes across the membrane.

Answer 24

voltage-gated ion channels

Question 25

This principle states no matter how strong the stimulus, as long as it is greater than the threshold, AP will occur

Answer 25

all-or-none principle

Question 26

This period of an AP is when the cell has complete insensitivity to another stimulus, no matter its strength

Answer 26

absolute refractory period

Question 27

This period of an AP is when a stronger than threshold stimulus can initiate another AP

Answer 27

relative refractory period

Question 28

_______ _________ is the key in determining the direction of an AP

Answer 28

refractory period

Question 29

What is the key factor in the velocity/ current of an AP?

Answer 29

The larger the fiber diameter, the faster the AP propagates

Question 30

This is an insulator that speeds up the AP and allows less leakage of current

Answer 30

myelin sheath

Question 31

True or false- APs only are propagated at the nodes of Ranvier

Answer 31

true

Question 32

These drugs block voltage-gated Na+ channels

Answer 32

procaine (Novocaine) lidocaine cocaine

Question 33

This type of summation refers to lots of signals arriving at the same time, but at different parts of the dendrite

Answer 33

spatial summation

Question 34

This type of summation refers to repeated signals arriving at the same place which reinforces the signal

Answer 34

temporal summation

Question 35

This is the place on the neuron that is the "first domino"

Answer 35

axon hillock/ trigger zone