The pacinian corpuscle consists of the unmyelinated terminal part of an afferent nerve fiber that is surrounded by concentric lamellae formed by the membranes of numerous supporting cells. The axon…

In a myelinated nerve fiber, successive 1- to 2-mm segments of axon, called internodes, are enveloped by multiple layers of Schwann cell membrane. Between these segments are short lengths of…

Action Potential Propagation. Three stages illustrate the propagation of an action potential past a point on an axon at which microelectrodes have been positioned to record intracellular and extracellular potentials,…

At rest, the resting membrane potential, or the absolute difference in electrical potential between the inside and the outside of the inactive neuron, results predominantly from the membrane permeability to…

On neurophysiologic testing with motor nerve conduction studies (NCS), the pattern of changes in the recorded responses differs when focal neurapraxia occurs to the same degree and at the same…

The transmembrane ion concentrations at rest is dependent upon the passive diffusion of ions from the site of higher concentration to the site of lower concentration through ion channels, as…

1. In the free nerve ending, the peripheral process branches widely and ends without obvious specialization. These endings respond primarily to intense stimuli, and are thought to play a role…

A single nerve, such as the median or ulnar nerve, is composed of thousands of axons that are grouped into several distinct nerve fascicles (see Plate 6-1, top left). Each…

The structures of the nerve can be identified microscopically. At different magnifications, the definition and various individual components of the nerves can be identified. The upper image (see Plate 6-2)…

Clinical definition of the distribution of sensory changes affecting a specific area within one extremity implies a single nerve root, portion of a plexus, or peripheral nerve damage. Focal complaints…