Physiology 2130 Lecture 4: Module 4 - Nerve cells

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: John Bell

Document Summary

Nerve cells and muscle cells are considered excitable bc they can use the resting membrane potential to generate an electrochemical impulse called an action potential. Action potential is the language of the nervous system bc this is the way nerve cells communicate with one another. Action potential is a rapid reversal of the resting membrane. The membrane potential rapidly changes from -70 mv to roughly +35 mv. This sudden change to a more positive value is called depolarization. After this phase the membrane potential rapidly returns to -70 mv this is called repolarization. The membrane potential then briefly bc more negative, reaching ~90 mv hyperpolarization. After this very negative phase, membr potential returns to the resting levels of -70. -the movement of ions across the membrane--mainly na and k ions. 2 very special types of channels found in nerve & muscle cells: voltage-gated sodium and voltage-gated potassium channels.