Internal carotid plexus

File:Horner's Syndrome and Autonomic innervation of the eye.svg

Scheme showing sympathetic and parasympathetic innervation of the pupil and sites of lesion in a Horner's syndrome.

The internal carotid plexus is a nerve plexus situated upon the lateral side of the internal carotid artery. It is composed of post-ganglionic sympathetic fibres which have synapsed at (i.e. have their nerve cell bodies at) the superior cervical ganglion. The plexus gives rise to the deep petrosal nerve.

Anatomy

Postganglionic sympathetic fibres ascend from the superior cervical ganglion, along the walls of the internal carotid artery, to enter the internal carotid plexus. These fibres are then distributed to deep structures, including the superior tarsal muscle and pupillary dilator muscle. It includes fibres destined for the pupillary dilator muscle as part of a neural circuit regulating pupillary dilatation component of the pupillary reflex. Some fibres of the plexus converge to form the deep petrosal nerve.

The internal carotid plexus communicates with the trigeminal ganglion, the abducent nerve, and the pterygopalatine ganglion (also named sphenopalatine); it distributes filaments to the wall of the internal carotid artery, and also communicates with the tympanic branch of the glossopharyngeal nerve.

The plexus there occasionally presents a small gangliform swelling - the carotid ganglion - on the under surface of the artery.

Additional images

• Nerves of the orbit, and the ciliary ganglion. Side view.
  Nerves of the orbit, and the ciliary ganglion. Side view.
• Pathways in the ciliary ganglion.
  Pathways in the ciliary ganglion.

References

Public domain This article incorporates text in the public domain from Template:Wikidatathe 20th edition of Gray's Anatomy (1918) Template:Main other

Notes

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