Every step we take begins with a burst of calcium inside our muscle cells, causing them to contract. To prepare for action, the cells keep calcium locked in an internal compartment, the sarcoplasmic reticulum. Studding its membrane are thousands of RyR1 channels—the largest known ion channels—t...
Source: [Phys.org](https://phys.org/news/2026-09-calcium-channels-muscle-cells.html)