Physiology 3120 Lecture Notes - Lecture 8: Resting Potential, Axon Hillock, Electrochemical Gradient

• School: Western University
• Department: Physiology
• Course: Physiology 3120
• Professor: Anita Woods

Document Summary

Excitable cells (like nerve cells and muscle cells) are capable of generating electrochemical impulses at their membranes from the rmp. In some cases, utilization of these impulses to transmit signals along the membranes. Need 2 nerve cells: first nerve cell: pre-synaptic nerve cell, second nerve cell: post-synaptic nerve cell, where the two nerves come into contact: synapse. Cell body contains nucleus, dendrites (receive input from pre-synaptic nerve) Ap begins at axon hillock (most electrically sensitive part of nerve cell; high concentration of voltage gated channels) Myelinated: myelin sheath allows ap to travel faster down the axon to the axon terminal. Axon terminal synapse onto the post synaptic cell. In order to excite the post synaptic cell, have to get stimulus from pre-synaptic cell: causes changes in ion permeability to trigger ap. The action potential (ap) is a rapid reversal of the resting membrane potential: rapidly goes from -70 mv to + 40mv.