Answer:
Depolarization of the sarcolemma means that the inside of the membrane has become less negative as sodium ions accumulate.
Explanation:
Depolarization consists of a decrease in membrane potential, promoted by the movement of ions that generates a change in this membrane potential at the intracellular level.
At rest, the intracellular space tends to have a negative membrane potential, with respect to the extracellular one. The entrance of sodium ions (Na⁺) through the membrane produces a change, in which the intracellular membrane potential will be less negative.
In the sarcolemma, the entrance of Na⁺ ions produces a decrease of the negativity of the membrane potential, with the exit of intracellular calcium, by the sarcoplasmic reticulum. This is the mechanism responsible for initiating muscle contraction.
