2. Muscle contraction:
Calcium is a major ion that plays a role in muscle contraction when an action potential is generated in the neuromuscular junction and propagates through the muscle fiber it activates voltage-gated calcium channels and this influx of calcium diffuses in the cytoplasm between actin and myosin filaments of the muscle which makes them glide over each other triggering muscle contraction and as the action potential fades the calcium ions get stored back to be released again with the new action potential.
