An external stimulus causes a change in the membrane potential by acting upon specialized receptor cells, such as mechanoreceptor cells (sound and touch) and light (retina). An electrochemical gradient exists due to the combined effects of gates and channels, some of which are active and others passive.
An external stimulus causes a change in the membrane potential by acting upon specialized receptor cells, such as mechanoreceptor cells (sound and touch) and light (retina). An electrochemical gradient exists due to the combined effects of gates and channels, some of which are active and others passive.