Psych M.D. - Axon


Term: Axon
Definition (Myers):the extention of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
Definition (alternative): A long fiber of a nerve cell (a neuron) that acts somewhat like a fiber-optic cable carrying outgoing (efferent) messages. *
Contextual explanation: The main purpose of the axon is to send impulses away from the cell body to neuron dendrite. A nerve impulse travels from a dendrite, to the cell body, and down the axon to dendrites from other neurons. Once the impulse reaches the synapse, neurotransmitters, chemicals, which excite or calm effecter or neurons, diffuse into the extra cellular space and reach the dendrite, once again turning into an impulse. Protecting and insulating electric fibers from one another is the myelin sheath. It is a whitish, fatty, segmented sheath which covers the majority of nerve fibers and helps transmit nerve impulses faster.
Related terms and concepts: Myelin Sheath
Neuron
axon
Related websites: http://today.uci.edu/news/images/axon1_head.jpg http://www.youtube.com/watch?v=9EMpPJM1U-s http://psych.athabascau.ca/html/Psych289/Biotutorials/1/axon.shtml?sso=true
http://www.medterms.com/script/main/art.asp?articlekey=7797
Edited by: Tom


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