Carotid

Carotid, the great artery concerned with the supply of blood to the head. The common carotid of the right side of the neck takes origin at the bifurcation of the arteria innominata, that of the left side springs directly from the aorta. The vessels of the two sides have a nearly identical course in the neck, despite their different origins, they run upwards in the same sheath with the pneumogastric nerve and internal jugular vein; at the upper border of the thyroid cartilage each common carotid divides into an external and internal branch. The external carotid artery conveys blood to the face by its facial branch, to the tongue by the lingual, to the scalp by the occipital and posterior auricular, to the pharynx by the ascending pharyngeal, to the thyroid gland by the superior thyroid, and finally divides into the superficial temporal and internal maxillary branches. The internal carotid enters the cranial cavity by the carotid canal of the temporal bone, it gives off an ophthalmic branch, and divides into the anterior and middle cerebral arteries which supply the brain.