Describe in order the contraction mechanism in a skeletal muscle cell.
-Depolarization occurs; and the action potential is generated
-The action potential, carried deep into the cell by the T Tubules, triggers the release of calcium ions from the sarcoplasmic reticulum.
-Calcium Ion concentrations at myofilaments increase; myofilaments slide past one another, and the cell shortens
-The concentration of the calcium ions at the myofilaments decreases as they are actively transported into the sarcoplasmic reticulum
-Muscle cell relaxes and lengthens