Axon: Each neuron has a single axon. Arises from a cone-shaped region of the cell body called the axon hillock The axon tapers to form a slender process that remains uniform in diameter for the rest of its length. In some neurons, the axon is very short or absent. In others it is long and accounts for nearly the entire length of the neuron (3-4 feet). Any long axon is called a nerve fiber. Axons with the largest diameters conduct impulses the most rapidly. Axons give off occasional branches along their length called axon collaterals. Axons branch profusely at its end: 10,000 or more telodendria, or end branches per neuron. The bulbous distal endings of the telodendria are called axonal terminals. Functionally, axons are the conducting component; they generate nerve impulses and transmit them away from the cell body. In motor neurons, the nerve impulse is generated at the axon hillock and conducted along the axon to the axonal terminals. Neurotransmitters excite or inhibit neurons with which the axon is in close
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This note was uploaded on 11/22/2011 for the course BSC BSC1085 taught by Professor Sharonsimpson during the Fall '10 term at Broward College.