Cellular Physiology of Nerve Cellspart

Part I focused on general properties that are shared by all cells. Every cell must achieve osmotic balance, and all cells have an electrical membrane potential. Part II considers properties that are peculiar to particular kinds of cells: those that are capable of modulating their membrane potential in response to stimulation from the environment. These cells are called excitable cells because they can generate active electrical responses that serve as signals or triggers for other events. The most notable examples of excitable cells are the cells of the nervous system, which are called neurons.

The nervous system must receive information from the environment, transmit and analyze that information, and coordinate an appropriate action in response. The signals passed along in the nervous system are electrical signals, produced by modulating the membrane potential. Part II describes these electrical signals, including how the signals arise, how they propagate, and how the signals are passed along from one neuron to another. We will see that simple modifications of the scheme for the origin of the membrane potential, presented in Chapter 5, can explain how neurons carry out their vital signaling functions.

0 0

Post a comment