Figure 16-6 Schematic representation of the autonomic nervous system depicting the functional innervation of peripheral effector organs and the anatomic origin of peripheral autonomic nerves from the spinal cord. Although both paravertebral sympathetic ganglia chains are presented, the sympathetic innervation to the peripheral effector organs is shown only on the right part of the figure, whereas the parasympathetic innervation of peripheral effector organs is depicted on the left. The roman numerals on nerves originating in the tectal region of the brainstem refer to the cranial nerves that provide parasympathetic outflow to the effector organs of the head, neck, and trunk. (From Ruffolo R: Physiology and biochemistry of the peripheral autonomic nervous system. In Wingard L, Brody T, Larner J, et al [eds]: Human Pharmacology: Molecular to Clinical. St. Louis, Mosby-Year Book, 1991, p 77.)