Action Potentials

Neurons are located throughout the entire body, sending electrical signals to trasnmit information to different organs, muscles, or tissues. These electrical signals are produced by the movement of different ions across the membrane of the neuron. Ions have different charges associated with them. Ions usually require different channels or pumps to move across the membrane. The sodium/potassium pump is essential to the movemen of sodium and potassium, obviously. There are various other channels or pumps that are utilized to transfer ions across the membrane. There are "leak channels" that allow ions to flow through the membrane and stay around their equilibrium. When there is enough ion movement to bring the membrane potential about about -40mV, then an action potential takes place. The action potential propogates charge down the neuron's membrane and sends the electrical signal. This happens in the central nervous system, as well as the peripheral nervous system.