Coccygeal ganglion - (g. copusculum anococae) is located in the lateral surface of the middle sacral muscle. Dimensions from 6 to 20 mm and located at a depth of 2.5 to 7 cm from the skin. Formed by sclerotomy from perineural membranes, intradermal bundles of superficial arteries and veins and fascia. Supplied by the coccygeal branch of the circumferential artery and the coccygeal plexus (S. coccae n.). It is a modified umbilical lymph node that has turned into an exocrine gland. Contains a homogeneous whitish viscous substance (smegma). The head of the ganglion is covered with connective tissue, covered by a bursa, and partly intimately fuses with the fibers of the coccygeal nerve, and sometimes with the transverse spinalis and posterior superior gluteal muscles. Function g. copua anococsi is not identified.