Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
The superior cervical ganglion (SCG), the largest of the cervical ganglia, is placed opposite the second and third cervical vertebræ. It contains neurons that supply sympathetic innervation to the face.
It is of a reddish-gray color, and usually fusiform in shape; sometimes broad and flattened, and occasionally constricted at intervals; it is believed to be formed by the coalescence of four ganglia, corresponding to the upper four cervical nerves.
It is in relation, in front, with the sheath of the internal carotid artery and internal jugular vein; behind, with the Longus capitis muscle.
It receives input from the ciliospinal center.
The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses.
Diagram of efferent sympathetic nervous system.
Sympathetic connections of the ciliary and superior cervical ganglia.
The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
de:Ganglion cervicale superius