ganglion impar

Near the coccyx, the right and left sympathetic trunks join to form the ganglion impar.

See 'Ganglion impar' for the nerves near the coccyx.

Well-known structures incorporating this nomenclature include the azygos vein, ganglion impar, and the anatomical variant known as the azygos lobe of the lung.

Below, the two pelvic sympathetic trunks converge, and end on the front of the coccyx in a small ganglion, the ganglion impar (or ganglion of Walther).

Tailbone pain physicians specializing in Physical Medicine and Rehabilitation at New Jersey Medical School have published that sometimes even just a single local nerve block injection at the ganglion impar can give 100% relief of coccydynia when performed under fluoroscopic guidance.

The superior end of it is continued upward through the carotid canal into the skull, and forms a plexus on the internal carotid artery; the inferior part travels in front of the coccyx, where it converges with the other trunk at a structure known as the ganglion impar.