Internal Carotid Artery
The Internal Carotid Artery arises at the bifurcation of the common carotid artery near the superior horn of the thyroid cartilage. It has no named branches in the neck. It ascends within the carotid sheath to enter the cranial cavity via the carotid canal.

The internal carotid arteries contribute the major portion of the arterial supply of the brain (anterior and middle cerebral).

A common site for a carotid endarterectomy (opening the artery and stripping off the plaque with the adjacent intima) is the internal carotid artery, just superior to its origin. The internal carotid contributes to the arterial Circle of Willis. Unilateral neurologic symptoms and signs suggest carotid ischemia, whereas, bilateral symptoms and signs implicate vertebrobasilar ischemia. Clinically, middle cerebral artery occlusion includes contralateral hemiparesis and sensory loss (worse in arms and face); vertebrobasilar occulsion is dominated by the presence of vertigo, ataxia, ipsilateral sensory loss in the face, and contralateral hemiparesis and sensory loss in the trunk and limbs.