The nerve impulse that initiates muscular contraction

Q. The nerve impulse that initiates muscular contraction

1. begins with the binding of acetyl choline to receptors in the sarcoplasmic reticulum
2. causes both the plasma membrane and the transverse tubules to undergo hyperpolariation
3. causes opening of calcium channels which lead to an increase in calcium contreation within the sarcomere
4. prevents sodium entering the sarcomere

Answer: causes opening of calcium channels which lead to an increase in calcium contreation within the sarcomere