Internal Carotid Plexus, Inferior View

Description

Arising from the superior cervical ganglion, the internal carotid plexus forms a periarterial sympathetic network that ascends on the internal carotid artery as it enters the carotid canal, with fine yellow filaments wrapping circumferentially and sending small branches medially toward the cavernous sinus region. From an inferior perspective you would expect to appreciate the relationship of these nerves to the proximal cervical segment of the artery, with the plexus positioned immediately external to the arterial adventitia and deep to the prevertebral fascia. Nearby landmarks often included in this angle include the carotid bifurcation inferiorly and the jugular foramen region posterolaterally, where cranial nerves IX, X, and XI descend in close company with the internal jugular vein. Clinically, this view matters because the internal carotid sympathetic plexus is the conduit for postganglionic fibers that ultimately reach the eye and face, including the pathway that joins the abducens nerve and the ophthalmic division of the trigeminal nerve within the cavernous sinus. Small disruptions along the cervical internal carotid artery, classically carotid artery dissection, can injure these periarterial fibers and produce painful partial Horner syndrome (ptosis and miosis without anhidrosis). Surgeons also encounter this anatomy during carotid endarterectomy and high cervical vascular exposure, where traction or cautery near the artery can create transient sympathetic deficits. A tight corridor. Use this artwork for teaching head and neck autonomic pathways in gross anatomy, neuroanatomy, or neuroscience blocks, and for figure support in publications discussing carotid dissection, cavernous sinus syndromes, cluster headache mechanisms, or sympathetic chain lesions. It also fits operative anatomy manuals that need a clean explanation of periarterial sympathetic plexuses without the clutter of full cranial base dissection. Anatomical accuracy verified by SciePro's Medical Advisory Board.