week 2-neurons and action potential

Question 1

All living cells have an electric charge across their membrane, which results in a voltage or ____ difference between the inside and outside of the cell.

Answer 1

potential

Question 2

The ____ ____ is caused by a difference in concentration of individual ____ between the inside and outside of the cell (also called a ____ gradient) with some ions passing through more easily than others (a “____ membrane”)

Answer 2

membrane potential; ions; concentration; semipermeable

Question 3

At the resting potential, voltage-gated Na+ channels are ____. When the membrane is ____, conformational changes ____ the voltage-gated channel.

Answer 3

closed; depolarized; open

Question 4

Potassium channels are ____ gated and open when ____ reaches a threshold and stay that way until the cell ____

Answer 4

voltage; depolarization; hyperpolarizes

Question 5

____ gated sodium channels open and close ____

Answer 5

voltage; immediately

Question 6

The ____ ____ pump is always working!

Answer 6

Sodium/potassium (3 Na out for 2 K)

Question 7

No depolarization can happen during the ____ refractory period, but it may happen in the ____ refractory period if there is enough excitation

Answer 7

absolute; relative

Question 8

The ____ refractory period is depolarized, whereas the ____ refractory period is hyperpolarized

Answer 8

absolute; relative

Question 9

If two subthreshold potentials arrive at the trigger zone (____ ____) within a short period of time, they may ____ and initiate an action potential. This is called ____

Answer 9

axon hillock; sum; summation

Question 10

At the terminal voltage gated ____ channels open. The ion then signals movement of ____ to the membrane to dump their contents outside the cell.

Answer 10

Calcium; vesicles