Physiology 2130 Lecture Notes - Lecture 4: Oligodendrocyte, Choline, Exocytosis
10 Oct 2015
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Document Summary
Nerve and muscle cells are considered excitable cells because they can use the resting membrane potentials to create an electrochemical impulse called an action potential. The action potential is how the nerve cells (neurons) communicate with one another. Multipolar neuron (many different types we will learn) Action potential is a quick reversal of the resting membrane potential. From recording inside the cell the membrane resting potential changes from. 70mv to roughly +35mv- this sudden change to a positive value is called depolarization. Afterwards it quickly returns to -70mv called repolarization. The membrane then reaches around -90mv called hyperpolarization, after this negative phase returns to -70mv. The rapid changes are caused by ions crossing the membrane (mostly sodium and potassium) which are allowed to move through the membrane using channels. 2 types found in nerve and muscle cells : potassium voltage-gated channel and sodium voltage-gated channel.
