axon

Also ax·one

[ak-son]

noun

1. Cell Biology.,  the appendage of the neuron that transmits impulses away from the cell body.

axon

/ ˈæksəʊn, ˈæksɒn /

noun

1. the long threadlike extension of a nerve cell that conducts nerve impulses from the cell body Compare dendrite

axon

1. The long portion of a neuron that conducts impulses away from the body of the cell.

2. Also called nerve fiber

axon

1. The part of a nerve cell or neuron that transfers a nerve impulse from the nerve cell body to a synapse with another cell. (See action potential.) Depending on the location of the cell, the length of an axon can vary widely. In some cases (such as the axons that form the spinal cord), they may be several feet long.

Other Word Forms

• axonal adjective

Word History and Origins

Origin of axon¹

1835–45; < New Latin < Greek áxōn an axle, axis; akin to Latin axis

Word History and Origins

Origin of axon¹

C19: via New Latin from Greek: axis, axle, vertebra

Example Sentences

"Understanding the structure of axons is important for understanding brain cell signaling," says Shigeki Watanabe, Ph.D., associate professor of cell biology and neuroscience at the Johns Hopkins University School of Medicine.

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Since the mid-1960s, microscopists have seen that axons can scrunch up to form beads when they are diseased or under other stress.

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These signals get transmitted through the granule cells' axons -- their arm-like extension, known as mossy fibers.

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"The activity of a neuron can regulate the extent to which its axon is myelinated."

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These axons form bundles that make up white matter in the brain and play a large role in learning and communication between different brain regions.

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When To Use

What is an axon?

The axon is the part of the neuron that carries impulses away from the cell body.Neurons are the cells that gather information in the form of impulses and send them throughout the body. The neuron is made up of the cell body, the dendrites, and the axon.The axon, also called the nerve fiber, resembles a long, threadlike fiber. Most neurons only have a single axon. In vertebrates, the axon is covered by a myelin sheath made mostly of fat, protein, and water. The sheath increases the speed that impulses travel.The axon’s job is to move the impulses away from the cell body to another neuron or a muscle. The travel process is similar to electricity moving down a wire. At the end of an axon are bulbous structures called axon terminals, which form special junctions that connect the axon to other neurons or muscles. These junctions, called synapses, involve tiny gaps that the impulse jumps over to leave the axon. The impulse then travels through the new neuron and will eventually move through another axon. This process will repeat until the impulse reaches its destination.