PSIO 303A Lecture Notes - Lecture 34: Resting Potential, Reversal Potential, Saltatory Conduction

• School: University of Arizona
• Department: Physiology
• Course: PSIO 303A
• Professor: Eric Price, Steven Wright, Nick Delamere

Document Summary

Block 3 - lecture 4 - nervous action continuation. Know that certain ion channels are (cid:862)gated(cid:863) to open/close in response to a change in transmembrane voltage. Other ion channels are gated by binding/release of a chemical ligand. List in order the principal events associated with an action potential. Understand the (cid:862)threshold(cid:863) for the neuronal action potential. Understand myelination, the cells that are involved, nodes of ranvier and saltatory conduction. Be able to compare and contrast the characteristics of graded potentials vs. action potentials. Opened when a signal molecule (e. g. nt) binds to the channel protein. Occur in dendrite and soma of the neuron. Size of the potential varies with the strength of the stimulus. Depolarization to a threshold value causes voltage gated na+ channels to open. Opening of na+ channels --> increased na+ permeability --> na+ enters cell --> membrane potential is now positive as it reaches na+ nernst potential --> depolarization.