Action Potentials

Action potentials are ___ or ____. If threshold is met, an action potential will occur.

all, none

What do action potentials travel down?

axon

Where do action potentials start and travel to?

axon hillock, axon terminal

What type of channels do axon potentials rely on?

voltage-gated channels

What channel opens first and causes the membrane potential to get as high as 35 mV?

voltage-gated sodium channels

What is 35 mV?

depolarization

After voltage-gated sodium channels close what channels open?

voltage-gated potassium channels

Potassium ions move out of the cell and the cell ____.

repolarizes

The voltage-gated potassium channels stay open for a bit too long and the cell _____. This keeps the actional potential moving in one direction.

hyperpolarizes

The opening and closing of these channels stimulate the next set of channels and this continues all the way down the axon- this is known as ____ conduction.

continuous 

Continuous conduction is not as fast as ____ conduction where these channels only open and close at the nodes of Ranvier.

saltatory

What creates nodes of Ranvier?

myelination

What else can make action potentials travel faster?

• myelination

• larger diameter (because of less friction)