Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
1. Any of the autonomic nerve plexuses that coat the carotid arteries; all carotid plexuses receive postganglionic sympathetic axons from the superior cervical ganglia. The external carotid plexus sends axons to the smooth muscles of the face and upper neck, along branches of the external carotid artery. The internal carotid plexus sends axons to the trigeminal and ciliary ganglia, and the oculomotor, trochlear, ophthalmic, abducens, and glossopharyngeal nerves. Some axons leave the internal carotid artery at the foramen lacerum, inside the skull, to form the deep petrosal nerve, which runs to the pterygoid ganglion. Other carotid plexus axons continue along the anterior and middle cerebral arteries to provide sympathetic innervation of arteries of the brain.
2. A venous plexus that exits the skull through the carotid canal and interconnects the cavernous sinus inside the skull with the internal jugular vein outside the skull.
See also: plexus