The Axon

The axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma. It is a crucial part of the nervous system and plays a key role in transmitting information from one neuron to another, as well as to other cells in the body.

Structure of the Axon

The axon is a specialized structure with a unique composition. It is covered by a fatty insulating layer called the myelin sheath, which helps to speed up the transmission of electrical impulses along the axon. The myelin sheath is made up of Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In between the myelin sheath are small gaps called nodes of Ranvier, which also aid in the rapid conduction of impulses.

Function of the Axon

When a neuron receives a signal, it generates an electrical impulse called an action potential. This action potential travels down the axon, away from the cell body, and towards the axon terminals. At the axon terminals, the electrical impulse triggers the release of chemical messengers called neurotransmitters, which then transmit the signal to the next neuron or target cell.

Study Guide

1. What is the function of the axon in a neuron?
2. Describe the structure of the myelin sheath and its role in the transmission of electrical impulses.
3. Explain how an action potential travels along the axon and reaches the axon terminals.
4. What are the nodes of Ranvier and what role do they play in the conduction of impulses?
5. How does the axon contribute to the communication between neurons and other cells in the body?