When a muscle receives a signal from the nerves around it, the signal travels down the cell's membrane in folds called t-tubules. What will happen next to continue the contraction process?

The nerves send a message to the muscle asking them to reach out and contract. When the muscle receives a signal from the nerves around it, the signal travels down the cell's membrane in folds called t-tubules. When the signal reaches the sarcoplasmic reticulum the calciumpumps open allowing calcium ions