Petrous Segment Internal Carotid Artery Extends from base of skull to apex of petrous bone Enters cranial vault via foramen lacerum. Branches normally not seen angiographically - may be enlarged with carotid occlusive disease. Extends to the base of the skull. No branches normally seen. Posterior Communicating Artery Second branch of supraclinoid internal carotid.
Supplies thalamus, hypothalamus, optic chiasm, and mamillary bodies.
Common site for aneurysms. Supplies globe, orbit, frontal scalp, the frontal and ethmoidal sinuses. Ophthalmic artery branches anastamose with Maxillary artery branches - potential for collateral flow in cases of proximal carotid occulsion. Last branch to originate from Internal Carotid Artery. Supplies choroid plexus of anterior portion of temporal horn of lateral ventricles.