A "Resting" Motor Neuron is Expected To

Question

A "resting" motor neuron is expected to
A)release lots of acetylcholine.
B)have high permeability to sodium ions.
C)be equally permeable to sodium and potassium ions.
D)exhibit a resting potential that is more negative than the "threshold" potential.
E)have a higher concentration of sodium ions on the inside of the cell than on the outside.

Accepted Answer

Resting motor neurons usually have a resting potential that is more negative than the "threshold" potential, which is the membrane potential necessary to trigger an action potential. When the membrane potential reaches the threshold potential, sodium channels open and depolarization occurs, leading to the generation of an action potential. Therefore, a resting motor neuron should have a membrane potential that is less than the threshold potential, which is typically around -50 to -55 mV. This is achieved by having a higher concentration of potassium ions inside the cell and a higher concentration of sodium ions outside the cell, which creates an electrochemical gradient that favors the movement of potassium ions out of the cell and sodium ions into the cell. This results in a negative resting potential, typically around -70 mV.