Definitions

Axon - Nerve fibers (long chutes) that act as delivery pathways for electrical signals traveling from one site to another within the central nervous system (the brain and spinal cord) or from the central nervous system to sites all over the body.

Central Nervous System - Control center for entire system. Consists of the brain, spinal cord and optic nerves.

Dendrites – A nerve cell process carrying an impulse toward the cell body.

Nucleus – a spheroid body within a cell. It contains the hereditary factors of the cell.

Myelin - A soft, white coating of nerve fibers in the central nervous system, composed of lipids (fats) and protein. Myelin serves as insulation and as an aid to efficient nerve fiber conduction. When myelin is damaged in MS, nerve fiber conduction is faulty or absent. Impaired bodily functions or altered sensations associated with those demyelinated nerve fibers are identified as symptoms of MS in various parts of the body.

Nerve - A bundle of nerve fibers (axons). The fibers are either afferent (leading toward the brain and serving in the perception of sensory stimuli of the skin, joints, muscles, and inner organs.

Nervous system - Includes all of the neural structures in the body: the central nervous system consists of the brain, spinal cord, and optic nerves; the peripheral nervous system consists of the nerve roots, nerve plexi, and nerves throughout the body.

Neuron - The basic nerve cell of the nervous system. A neuron consists of a nucleus within a cell body and one or more processes (extensions) called dendrites and axons.

Oligodendrocyte - A type of cell in the central nervous system that is responsible for making and supporting myelin.

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