At rest, a neuron has a high concentration of ____ inside the cell and a high concentration of ____ outside the cell.

A) acetylcholine; chlorine
B) sodium; potassium
C) potassium; sodium
D) calcium; phosphorus
E) phosphorus; calcium

Neuron

Specialized signaling cell in nervous tissue; transmits electrical signals along its plasma membrane and sends chemical messages to other cells via its endings.

Sodium

A soft, silvery-white, highly reactive metallic element, essential for numerous biological processes in animals and humans, particularly in nerve and muscle function.

Potassium

A chemical element with the symbol K, essential for many processes in organisms, especially in nerve function.