Download Arteries of the Head and Neck

Arteries of the Head and Neck
The paired common carotid arteries supply the head and neck and three
paired branches of the right and left subclavian arteries: the vertebral
arteries, thyrocervical trunks, and costocervical trunks.
Common Carotid Arteries
Branches of the common carotid arteries supply blood to the head and
brain. The right common carotid originates from the brachiocephalic
trunk. The left common carotid is the second branch of the aortic arch.
At the "Adam's apple," the common carotids divide into the external and
internal carotid arteries.
The external carotid artery supplies most external head structures,
except the orbits. It gives rise to thesuperior thyroid artery, which
supplies the thyroid gland and larynx; the lingual artery, which
supplies the tongue; the facial artery, which supplies the skin and
muscles of face; the occipital artery, which supplies the posterior
scalp; the maxillary artery, which supplies the teeth, maxilla, buccal
cavity, external ear; and the superficial temporal artery, which
supplies the chewing muscles, nasal cavity, lateral aspect of face, most of
the scalp, and the dura mater around brain. A branch of the maxillary
artery, the middle meningeal artery, supplies the dura mater and
cranial cavity. Injury to the head that ruptures the middle meningeal
artery causes epidural hematoma, which can be fatal.
The internal carotid artery supplies the orbits and more than 80 percent
of the cerebrum. It gives rise to the ophthalmic artery, which
supplies the orbits, nose, and forehead; the anterior cerebral artery,
which supplies the medial aspect of the cerebral hemisphere, and
the middle cerebral artery, which supplies the lateral aspect of
temporal and parietal lobes. The internal carotid arteries have a carotid
sinus with baroreceptors that help regulate BP. Pressure on the neck
near the carotid sinuses can cause unconsciousness, because it simulates
high blood pressure, eliciting a reflex vasodilation and interfering with
blood flow to the brain.
Vertebral Arteries
Branches of the vertebral arteries supply blood to the neck structures
and the spinal cord. They originate from the subclavian arteries at the
base of the neck and unite in the brain stem to form the basilar artery.
The basilar artery branches supply the cerebellum, pons, and inner ear.
At the junction of the pons and midbrain, the basilar artery flows into
the arterial circle where it divides into two posterior cerebral arteries
that supply the occipital lobes and inferior portions of temporal lobes.
The thyrocervical trunks supply the thyroid gland and some
scapular muscles. They are small vessels that originate from the
subclavian arteries. Costocervical trunks arise from the subclavian
arteries and supply blood to the deep neck muscles and some intercostal
muscles of superior rib cage.
Arterial Circle
The arterial circle, also called the circle of Willis, is an arrangement of
arteries surrounding the pituitary gland and optic chiasm. It creates
redundancies to ensure blood supply to the brain if one artery feeding
the circle—or a part of the circle—is damaged. The arterial circle is fed
anteriorly by the left and right carotid arteries and posteriorly by the
basilar artery. The circle itself is composed of two posterior
communicating arteries, and one anterior communicating artery.
Branches off of the circle include two posterior cerebral arteries, two
middle cerebral arteries, and two anterior cerebral arteries.
Arteries of the Thorax
The wall of the thorax is supplied by a collection of arteries, some of
which originate directly from the thoracic aorta and others from
branches of the subclavian artery. Two bronchial arteries on the left and
one on the right deliver systemic blood to the lung structures, including
the visceral pleura, esophagus, and bronchi of lungs. Blood is also
delivered to the esophagus by the four or five esophageal arteries.
Numerous small mediastinal arteries deliver blood to the posterior
mediastinal structures.
Nine pairs of posterior intercostal arteries wrap around the rib cage
before anastomosing anteriorly with the anterior intercostal arteries.
The first pair arises from the costocervical trunk and the rest from the
thoracic aorta. They supply blood to the skin and subcutaneous tissue,
breasts, spinal cord and meninges, and pectoralis, intercostal, and some
abdominal muscles. The distribution of the subcostal arteries is similar
to that of the posterior intercostal arteries. They supply blood to the
posterior intercostal tissues, vertebrae, spinal cord, and deep muscles of
the back. One or more pairs of the small superior phrenic arteries supply
blood to the posterosuperior surface of diaphragm.
Internal thoracic arteries, also called the mammary arteries,
originate from the subclavian artery and supply the breast tissue. Their
branches, the anterior intercostal arteries, supply the intercostal
spaces anteriorly.