extends_fibers_into spinal nerve nerve plexus spinal nerve plexus an intermingling of fiber fascicles from adjacent spinal nerves to form a network. EHDAA2:0001899 somatic nerve plexus VHOG:0000925 UBERON:0001813 spinal nerve plexus To reach the muscles, dermatomes, and other structures of the limbs, some of the neurons in the spinal nerves come together in the plexus at the base of the limb. Such plexuses occur in all gnathostomes, and they reach their highest complexity among mammals and birds in which the cervical plexus supplies many ventral neck muscles, the brachial plexus supplies the pectoral appendage, a lumbosacral plexus supplies the pelvic appendage, and a coccygeal plexus supplies some of the pelvic muscles.[well established][VHOG] EMAPA:16987 plexus nervorum spinalium MA:0000235 plexus of spinal nerves FMA:5903 uberon UMLS:C0228603