Final answer:
The arterial supply to the head and neck primarily comes from the common carotid arteries, which branch into external and internal carotid arteries. The internal carotid arteries are responsible for supplying fresh, oxygenated blood to the brain.
Step-by-step explanation:
The majority of the arterial supply to the head and neck comes from the common carotid arteries. The right common carotid artery arises from the brachiocephalic artery and the left common carotid arises directly from the aortic arch. Both of these arteries give rise to the external and internal carotid arteries, which supply the respective sides of the head and neck with oxygenated blood. The internal carotid artery, specifically, enters the cranium to supply the brain with fresh, oxygenated blood, after emerging into the cranium via the carotid canal and carotid foramen.