What is an Action Potential?
An Action Potential is transmitted along nerve fibres and is the basic unit of pain signal that transmits to the brain. The Resting Membrane Potential (measured in mV) is the measured potential difference across a cell membrane of a sensory neuron or nerve cell. A variety of cellular permeable ions such as Na+, Ca++, K+ and Cl- will attempt to drive the membrane potential towards its electrochemical equilibrium. Once the membrane potential reaches the Threshold Potential, an Action Potential is inevitable, unless the nerve cell is being exposed to a steep magnetic field such as that produced by the Q Magnet. An Action Potential consists of a rapid Depolarisation (membrane potential becomes less –ve) followed by a Repolarisation (membrane potential becomes less +ve).