Axon

An axon is a long slender projection of a nerve cell or neuron found in most animals that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons, such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and many acquired neurological disorders that affect both the peripheral and central neurons. Vertebrate nerve fibers are classed into three types – group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C is unmyelinated. These groups include both sensory fibers and motor fibers. Another classification groups only the sensory fibers into four categories: Type I, Type II, Type III, and Type IV.