Calcium-induced calcium release (CICR)

Calcium-induced calcium release (CICR) is a process where an initial small increase in calcium within a cell triggers a larger release of calcium from internal storage areas, called the sarcoplasmic reticulum. This amplified calcium signal helps coordinate processes like muscle contraction. When calcium enters the cell, it activates channels on the sarcoplasmic reticulum, causing it to release even more calcium into the cell. This positive feedback loop ensures a rapid and strong response, essential for functions like heartbeat and muscle movements.