L3

Question 1

What is resting potential

Answer 1

Voltage difference across a nerve cell membrane when is not transmitting a impulse-usually -70 mv

Question 2

What is the main reason resting potential is negative

Answer 2

Sodium-potassium exchange pump

Question 3

What is a sodium-potassium exchange pump

Answer 3

What keeps a resting membrane negative-uses ATP to actively transport sodium ions out of the cell and pottsssium ions in-3Na+ out and 2k+ in= positive charge outside the cell

Question 4

What is action potential

Answer 4

The voltage difference across a nerve cell membrane when it’s excited

Question 5

What is a nerve impulse

Answer 5

A series of action potentials

Question 6

What is depolarization

Answer 6

Neuron receives stimulus to become more permeable to Na+, Na+ Chanel’s open while K+ stay closed. Na+ rush into the cell by diffusion and charge attraction

Question 7

What is repolarization

Answer 7

Positive inside causes Na+ Chanel’s to close, k+ Chanel’s open and diffuse out, restoring the original polarity

Question 8

What is hyperpolarization

Answer 8

When the K+ gates close to slowly, the outside become too posative

Question 9

What role does the sodium-potassium pump play in the refractory period?

Answer 9

Restores resting membrane potential