Healthcare Library

Nerve conduction

The nervous system is made up of two parts. Each part contains billions of neurons. The first part is the central nervous system. It contains the brain and spinal cord, which is a fibrous, ropelike structure that runs through the spinal column down the middle of the back. The other part is the peripheral nervous system. It consists of thousands of nerves that connect the spinal cord to muscles and sensory receptors. The peripheral nervous system is responsible for reflexes, which help the body avoid serious injury. It's also responsible for the fight or flight response that helps protect you when you feel stress or danger. Let's examine an individual neuron up close. Here is a peripheral nerve. Each one of the nerve bundles, or fascicles, contains hundreds of individual nerve. Here's an individual neuron, with its dendrites, axon, and cell body. The dendrites are tree-like structures. Their job is to receive signals from other neurons and from special sensory cells that tell us about our surroundings. The cell body is the headquarters of the neuron. It contains the cell's DNA. The axon transmits signals away from the cell body to other neurons. Many neurons are insulated like pieces of electrical wire. The insulation protects them and allows their signals to move faster along the axon. Without it, signals from the brain might never reach muscle groups in the limbs. Motor neurons are responsible for voluntary control of the muscles all over the body. The operation of the nervous system depends on how well neurons communicate. For an electrical signal to travel between two neurons, it must first be converted to a chemical signal. Then it crosses a space about a millionth of an inch wide. The space is called a synapse. The chemical signal is called a neurotransmitter. Neurotransmitters allow the billions of neurons in the nervous system to communicate with one another. That's what makes the nervous system the body's master communicator.

Nerve conduction

Review Date: 5/10/2019

Reviewed By: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Animations

Browse All

Videos

Browse All

In-Depth Animations

Browse All

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Content is best viewed in IE9 or above, Firefox and Google Chrome browser.

ways to give

view all

news room

view all

healthcare library

view all
Event Calendar

Hunterdon Healthcare offers an array of educational events, including childbirth, healthy living and fitness classes.

LEARN MORE
Health and Wellness Centers

Where health and fitness meet to help you stay healthy at every age.

LEARN MORE
Heart & Vascular

Heart and Vascular Services Department brings world-class cardiovascular care to our community.

LEARN MORE