Outside the cell there is a high concentration of __ ions

Na+

Inside the cell there is a high concentration of __ ions

K+

Is cell membrane more permeable to K+ or Na+?

K+

What are some larger anions (- charge) that are trapped inside

proteins, amino acids, and phosphates

Is the inside of the cell negative or positive charged?

Negative

Is the outside of the cell negative or positive charged?

Positive

What is the resting potential (mV)

-70

Charge difference is maintained by

Sodium-Potassium Pump (PUMP K IN) - three Na+ for every two K+ pulled in

Depolarization is triggered when?

A neuron is sufficiently stimulated

What happens in terms of K+/Na+ with depolarization?

K+ gates close, Na+ gates open

What happens during depolarization?

Na+ ions move in, neutralizing the negative charge inside Polarity inside/outside the axon switches Change called ACTION POTENTIAL

Does depolarization of one part of the axon cause neighboring Na+ channels to open?

Yes

What happens in repolarization?

Immediately after the Na+ gates have opened, K+ gates re-open and they move out of the cell This re-establishes polarity

What is the refractory period?

time between the triggering of an impulse along an axon and when it is available for next impulse (prevents same message from being transmitted backwards)

In order to be strong enough to send an impulse, a stimulus must reach the ________ potential

threshold potential Strength of the response is always the same