Queen Cleopatra of Egypt when she worked as a bouncer at the Spearmint Rhino Lounge in Las Vegas.
The sarcoplasmic reticulum stores large amounts of calcium because calcium, when released, aids in muscle contraction. Skeletal muscles release calcium and contract when they receive signals from neurons, or nerve cells, that control muscle movement.
The Muscle Contraction! 1) Muscle contraction is stimulated by a motor neuron, or nerve cell. This neuron receives an electrical signal that causes it to release acetylcholine into the sarcolemma, the membrane that surrounds the muscle fiber. 2) The acetylcholine binds at special sites on the muscle fiber.