Question

a&p flix quiz: events at the neuromuscular junction 6 parts | 0.83 of 1 point sodium and potassium ions do not diffuse in equal numbers through ligand - gated cation channels. why? the outside surface of the sarcolemma is negatively charged compared to the inside surface. potassium ions diffuse outward along favorable chemical and electrical gradients. the outside surface of the sarcolemma is negatively charged compared to the inside surface. sodium ions diffuse outward along favorable chemical and electrical gradients. the inside surface of the sarcolemma is negatively charged compared to the outside surface. potassium ions diffuse inward along favorable chemical and electrical gradients. the inside surface of the sarcolemma is negatively charged compared to the outside surface. sodium ions diffuse inward along favorable chemical and electrical gradients.

Explanation:

The resting - membrane potential of the muscle cell (sarcolemma) has an inside that is negatively charged relative to the outside. Sodium ions ($Na^+$) diffuse inward along favorable chemical and electrical gradients because there is a higher concentration of $Na^+$ outside the cell and the inside is negatively charged. Potassium ions ($K^+$) have a different equilibrium situation.

Answer:

The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.