NSCI 2222 Lecture Notes - Lecture 5: Sodium Channel, Cyclic Adenosine Monophosphate
14 Sep 2016
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Document Summary
Threshold can be reached by the speed of depolarization and by a certain voltage level depending on the cell. Threshold values are also much less static then we think. Inactivation of sodium channels is an entirely random process that takes place only after a certain amount of time. The peak of the ap results in no net charge. Absolute refractory period is when the sodium channels are inactivated and are not randomly opening. Relative refractory period is when ions are diffusing in their normal way. Its relative because its still possible but just much are to depolarize the cell because it is hyperpolarized. Sodium potassium pumps set up the system for having an electrical charge difference by establishing a concentration gradient for potassium in order for it leak out. Thus, allowing the cell to maintain a negative electrical charge. Ionotropic receptors have multiple receptor binding sites found on the surface on the channel.
