The Five Major Types of Protein Ion Channels are Calcium, Sodium, Nonselective, Chloride, and Potassium Flow of Ions through These Channels (Calcium and Sodium into Cells and Potassium Outward) Determines the Transmembrane Potential of Cells.

(From Ganong WF. Review of Medical Physiology. 21st ed. New York, NY: Lange Medical Books/McGraw-Hill; 2003.)

The five major types of protein ion channels are calcium, sodium, nonselective, chloride, and potassium. Flow of ions through these channels (calcium and sodium into cells and potassium outward) determines the transmembrane potential of cells.