Description
The ganglion impar is found at the sacrococcygeal joint on the ventral surface of the coccyx. The neurons of the ganglion impar originate as neural crest cells along the dorsolateral surface of the developing spinal cord. These cells migrate during development to their final position along the caudal end of the sympathetic chain. The ganglion impar supplies postganglionic sympathetic innervation to the perineal and perianal regions. These fibers travel to their targets with nerves of the coccygeal plexus.
Some visceral sensation from the pelvis travels back to the central nervous system via the ganglion impar. This is often interpreted as diffuse pain of the perineum and anus (Malec-Milewska et al., 2014).
Related parts of the anatomy
References
Malec-Milewska, M., Horosz, B., Koleda, I., Sekowska, A., Kucia, H., Kosson, D. and Jakiel, G. (2014) 'Neurolytic block of ganglion of Walther for the management of chronic pelvic pain', Wideochir Inne Tech Maloinwazyjne, 9(3), pp. 458-62.