Motor commands and action potential

Question 1

Membrane Potential

Answer 1

A difference in charge between the inside and outside of a cell

Question 2

Concentration Gradient

Answer 2

A difference in concentration of ions on the inside and outside of a cell; causes ions to flow through channels to reach equilibrium

Question 3

Voltage-Gated Channel

Answer 3

Requires only an impulse to open (K+ and Na+ channels) sodium-potassium pump: requires ATP to open; pump 3 Na+ out and 2 K+ in

Question 4

Resting Potential

Answer 4

Na+ and K+ channels are closed; remains in an off state; inside of axon is negative (-70 mV); more K+ on the inside vs outside; less Na+ on inside vs outside

Question 5

Repolarization

Answer 5

Na+ channels close; K+ channels open and K+ rushes out; K+ is equal on the inside and outside (no gradient); rush out of K+ ions cause the axon to be negative on the inside (-70 mV); no more gradients

Question 5

Depolarization

Answer 5

An impulse comes into the axon triggering Na+ channels to open; Na+ rushes in; Na+ is equal on the inside and outside (no gradient); rush in of Na+ ions cause the axon to be positive on the inside (+30 mV)

Question 6

Refractory Period

Answer 6

Na+ and K+ channels are closed because there is no electric impulse; to restore concentration gradients, sodium potassium pumps open (requires ATP); Na+ rushes out and K+ rushes in; restores the axon to resting potential state (-70 mV)