The term relates to the peripheral nervous system and refers to the outflow of nerve signals from the CNS to
a) the striated muscle cells of the heart
(b) the smooth muscle of the viscera, blood vessels and skin
(c) glandular cells of all kinds.
The visceral efference is mediated by two different systems:
1/ the sympathetic nervous system; sympatheticus.
2/ the parasympathetic nervous system; parasympatheticus.
Unlike the somatic efference where only one neuron connects the CNS to the effector cells (striated skeletal muscle), the visceral efference works with two series-connected neurons. One of these - the preganglionic nerve cell - has its cell body in the CNS (just like the alpha and gamma motor neurons) but ends in an autonomic ganglion where the signal is switched over to nerve cell number two - the postganglionic nerve cell. The postganglionic neuron then transmits its axon up to and contacts the effector cells.