The Common Vein Copyright 2010
The thyroid receives innervation from both the sympathetic and parasympathetic nervous systems, which are subsets of the autonomic nervous system.
Sympathetic input is supplied by the superior cervical ganglion and the cervicothoracic ganglion. The superior cervical ganglion lies posterior to the sheath of the internal carotid artery and internal jugular vein.
The parasympathetic input is supplied by the superior laryngeal nerve and the recurrent laryngeal nerve.