Physiology 2130 Lecture Notes - Lecture 4: Repolarization, Voltage-Gated Potassium Channel, Extracellular Fluid
25 Dec 2016
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Document Summary
Virtually all cell in body have membrane potentials. Excitable: can use resting membrane potential to generate action potential. Number of dendrites varies depending on where the cell is located. Cell body (soma): control center of the nerve cell, containing nucleus. Contains all necessary organelles for directing cellular activity. Acts as insulatorfor axon, forces ionic changes (that make up action potential) to take place only at nodes of ranvier: small exposed region. Jumping of action potential from node to node increases speed of transmissiondown the length of the axon. Established/maintained by electrochemical gradients of major intracellular/extracellular ions. Action potential: electrochemical impulse considered to be language of nervous system. Dendrites: thin branching processes of the cell body functioningto receive incoming signals. Increase overall surface area of neuron is it can communicate with other neurons. Axon: projection of cell body, carries outgoing signal to target cell in the form of an action potential. Myelinated: layered phospholipid membrane sheath wrapped around axon.
