<span>The unique aspect of norepinephrine release is that , they are released by axon Varicosities. Long postganglionic sympathetic fibers lead from the sympathetic chain to the target organ where they are terminated with bulbous enlargements called varicosities. The modified axon endings release a neurotransmitter, in the case of sympathetic nervous system norepinephrine, into its surroundings. Norepinephrine is known to be neurotransmitter for postganglionic sympathetic adrenergic nerves and functions by mobilizing the brain and body for action. Varicosities can be thought of as a series of small beads strung on a string, each axon has a relatively high number of these endings. The varicosities have no postsynaptic terminal assigned.</span><span />
