Coccygeal plexus
The coccygeal plexus is a small nervous plexus upon the pelvic surface of the coccygeus muscle.
This plexus is formed by the Ventral [ramus of spinal nerve|ventral rami] of the fourth and fifth sacral nerves, and the ventral ramus of the coccygeal nerve (Co). The relative contributions of S4 and S5 are minor and major, respectively. The coccygeal plexus gives rise to the anococcygeal nerve.
The coccygeal plexus is distributed to the coccygeus muscle, part of the levator ani muscle, the sacrococcygeal symphysis, and a small area of skin between the tip of the coccyx, and the anus.