Internal Carotid Arteries

The internal carotid arteries originate from the common carotid arteriers.

The common carotid arteries originate from the aortic arch on the left and the brachiocephalic trunk on the right.

The common carotid arteries bifurcate at the level of the thyroid cartilage into the external and internal carotid arteries.

The external carotid artery sends branches to the neck and face, whereas the internal carotid artery ascends to the base of the skull, entering the carotid canal.

Upon exiting the carotid canal, the internal carotid artery (in green) courses horizontally over the foramen lacerum and enters the cavernous sinus and, after turning superiorly, divides into its terminal branches.

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Ophthalmic artery. Courses through the optic canal to supply the retina, orbit and part of the scalp.
• • Posterior communicating artery. Joins the posterior cerebral artery with the internal carotid artery.
  • Anterior cerebral artery. Courses superior to the optic chiasma and enters the longitudinal cerebral fissures. The anterior cerebral artery courses superiorly and then posteriorly along the corpus callosum, providing blood supply to the medial sides of both cerebral hemispheres.
    • Anterior communicating artery. Is a very short artery that connects the two anterior cerebral arteries.
  • Middle cerebral artery. Courses into the lateral fissure between the parietal and temporal lobes. It sends many branches to the lateral sides of the cerebral hemispheres and central branches into the brain.