The first motor neurons have very long axons and synapse with the second motor neurons in the near vicinity of the target organs. As a consequence, the axons of the second motor neurons are relatively short.
Functionally, the sympathetic and parasympathetic systems often operate in opposition to each other. Many internal organs are stimulated by both systems. When one stimulates an organ, the other tends to depress the organ. The sympathetic system often produces the "fight-or-flight" reactions in organs preparing the organism for emergency situations. The parasympathetic system tends to inhibit these reactions. Thus, the response of an organ depends on the proportionate strength of stimulation supplied by each system at any given moment.
