Jr. The approach and organization of this material was developed by Bowman O. Davis, Jr. for specific use in online instruction. All rights reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without the written permission of the copyright owner. Before beginning this lecture material, read Chapter 48 to page 964 as a general review of basic neurophysiology. Don t forget to review the chemical and physical events of the action potential if you ve forgotten them.
Glial cells serve a variety of functions depending upon their specialization.
Schwann cells and oligodendroglial cells are glial cells of particular interest because they provide the myelin sheaths that characterize myelinated white matter and distinguish it from nonmyelinated gray matter . Neurites are of two types distinguished by the direction of conduction across them. Axons are neurites that conduct action potentials away from the cell body, while dendrites are neurites conducting toward the cell body. Nerves that comprise the PNS may be classified as sensory, motor or mixed depending upon the direction of conduction across them. Although a few purely sensory and purely motor nerves exist, the majority of peripheral nerves are mixed.