coccygeal plexus coccygeal plexus the coccygeal plexus is a nerve plexus near the coccyx bone. coccygeal plexusplan of sacral and pudendal plexuses.detailsfroms4-s5, coccygeal nervetoanococcygeal nerveidentifierslatinplexus coccygeusta98a14.2.07.044ta26598fma45356anatomical terms of neuroanatomy structure this plexus is formed by the ventral rami of the fourth and fifth sacral nerves, s4 & s5, and the ventral ramus of the coccygeal nerve, co. the relative contributions of s4 and s5 are minor and major, respectively. it gives rise to the anococcygeal nerve.