Arteries of the Head and Neck

The common carotid arteries and branches of the subclavian artery provide blood supply to the head and neck. The common carotid arteries divide into external and internal carotid arteries, while the subclavian artery gives rise to vertebral arteries and other branches. Together, these vessels ensure comprehensive perfusion of cranial and cervical structures.

The internal carotid arteries supply over 80% of the cerebrum and the orbits. These arteries enter the cranium and branch into the ophthalmic artery, which further divides into the anterior and middle cerebral arteries, providing critical blood flow to major brain regions.

The vertebral arteries rise from the subclavian arteries in the neck and supply the vertebrae, spinal cord, and deeper neck structures. Inside the cranium, the right and left vertebral arteries merge to form the basilar artery, which supplies the cerebellum, pons, and inner ear, providing critical posterior brain perfusion.

The circle of Willis is a circular anastomosis of arterial branches that ensures continuous blood supply to the brain even when one main artery is blocked. This redundant network serves as a safeguard against ischemic events such as strokes, representing a critical protective mechanism for maintaining cerebral perfusion during vascular compromise.

The external carotid arteries reach most head tissues except the brain and orbits. They branch into smaller arteries supplying the thyroid gland, larynx, tongue, anterior face, posterior scalp, and jaws, providing comprehensive perfusion to superficial and deep cervical structures throughout the head.

Occlusion of the internal carotid artery or its branches can lead to transient ischemic attacks or strokes, resulting in loss of consciousness or temporary neurological dysfunction. These events underscore the critical role internal carotid arteries play in maintaining brain health and highlight the importance of understanding blood pressure imbalances and circulatory shock in cerebrovascular disease.

The internal carotid artery branches into the anterior cerebral artery, which nourishes the frontal lobe, and the middle cerebral artery, which supplies the temporal and parietal lobes. These regions are particularly susceptible to cerebrovascular accidents, making these arterial branches critical for understanding stroke risk and brain perfusion patterns.