Which of the following parts is the house of calcium ions? A. Sarcolemma B. Sarcoplasmic reticulum C. Sarcosomes D. Nucleus
Option B The endoplasmic reticulum, i.e., sarcoplasmic reticulum of the muscle fibres is the storehouse of calcium ions. A neural signal reaching this junction releases a neurotransmitter (Acetylcholine) which generates an action potential in the sarcolemma. This spreads through the muscle fibre and causes the release of calcium ions into the sarcoplasm from the sarcoplasmic reticulum and initiate the mechanism of muscle contraction. Hence sarcoplasmic reticulum of muscle fibres is the storehouse of calcium.
