Ions

Ions are electrically charged salt particles. For instance, sodium, calcium, or chloride ions are charged salt particles.

The term ion is derived from the Greek word "ionos" (= the wanderer). They have been thus named because in an electric field they wander to one of the two poles. Ions play a significant part everywhere in the body. For example, the influx of ions through the ion channels in the muscle cells leads to contraction of the muscles. Ions also regulate the transmission of information to the nervous system.