The
superior cervical ganglion (
SCG) is part of the
autonomic nervous system (ANS) responsible for maintaining homeostasis of the body. More specifically it is part of the
sympathetic nervous system, a division of the ANS most commonly associated with the
fight or flight response. The ANS is composed of pathways that lead to and from
ganglia, groups of nerve cells. A ganglion allows a large amount of divergence in a neuronal pathway and also enables a more localized circuitry for control of the innervated targets. The SCG is the only ganglion in the sympathetic nervous system that innervates the head and neck. It is the largest and most rostral (superior) of the three
cervical ganglia. The SCG innervates many organs, glands and parts of the carotid system in the head.