Physiology 2130 Chapter Notes -Repolarization, Sarcolemma, Choline

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: all

Document Summary

Module 4 online notes (sec 4. 1 to 4. 31) Virtually all cells in the body have membrane potentials (inside being electrically negative relative to the extracellular fluid) Recall the ion concentrations and electrical distribution of a typical cell. The sizes of the ions represent their relative extra- and intracellular concentrations and the arrows show the associated concentration gradients for each ion. Certain cells are considered excitable because they can use the resting membrane potential to generate an electrochemical impulse called an action potential. These excitable cells include nerve cells and muscle cells. The action potential is the way nerve cells communicate with one another. Action potentials are also necessary for muscle contractions. Dendrites: thin branching processes of the cell body, whose function is to receive incoming signals. Dendrites increase the overall surface area of the neurons so that it can communicate with many other neurons.