The internal carotid artery is the larger of the two terminal divisions of the common carotid. It ascends perpendicularly by the side of the pharynx to the base of the skull. Here, it enters the carotid canal, in the petrous portion of the temporal bone. It lies at first on the outer side of the external carotid artery, and then behind it. At its origin it is more superficial than elsewhere and lies in the superior carotid triangle. As it ascends, it lays more deeply, passing beneath the parotid gland, the posterior belly of the digastric muscle, styloid process, stylopharyngeus and stylohyoid muscles. It is crossed by the hypoglossal and glossopharyngeal nerves, and the occipital and posterior auricular arteries. Externally, it is in close relation with the internal jugular veins and the pneumogastric nerve, and near the base of the skull with the glossopharyngeal, hypoglossal, and spinal accessory nerve. Behind, it is by the rectus capitis anticus major muscle, the superior ganglion of the sympathetic nerve, and the superior laryngeal nerve. It is covered by the skin, fascia, parotid gland, and the structures which pass between it and the external carotid artery – styloglossus, stylopharyngeus muscles, glossopharyngeal nerve, and the stylohyoid ligament.

Arteria carotis interna

Artère carotide interne