What is the purpose of the terminal cisternae within the sarcoplasmic reticulum?
a. to store sodium and potassium for cell hydration and pressure
b. to store actin and myosin
c. to store calcium
d. to store tropomyosin and troponin
Answer: c. to store calcium
The sarcoplasmic reticulum contains special sacs called terminal cisternae, which store calcium. the calcium works with troponin to help activate the muscle excitation process.