solar plexus /sō′lər/ [L, sol, sun, plexus, network] , a dense network of nerve fibers and ganglia that surrounds the roots of the celiac and the superior mesenteric arteries at the level of the first lumbar vertebra. It is one of the great autonomic plexuses of the body in which the nerve fibers of the sympathetic system and the parasympathetic system combine. The denser part of the solar plexus lies between the suprarenal glands, on the ventral surface of the crura of the diaphragm and on the abdominal aorta. Also called celiac plexus.
