This module explores some of the key roles played by ion channels and calcium ions in the communication that takes place within and between cells. The module is split into two linked themes. Firstly, an introduction to the diversity of ion channel families and their biological functions including the many different cellular processes throughout the life history of cells that are regulated by calcium ions as signals. Secondly, an investigation of the importance of ion channels and calcium signalling in animals, and human physiology in particular, using examples of diseases that are caused when ion channels malfunction (e.g. myotonia, malignant hyperthermia, sudden heart arrest caused by long QT syndrome.) or calcium signalling is disrupted (e.g. Alzheimer’s disease, polycystic kidney disease, pancreatitis). Students also gain hands-on experience of the techniques used to study ion channels and calcium signalling in cells.