Arteries of the head and neck

# Overview
Most arteries in the anterior cervical triangle arise from the common carotid artery or one of the branches of the external carotid artery.

# The Common Carotid Arteries
- The right common carotid artery begins at the bifurcation of the brachiocephalic trunk, posterior to the right sternoclavicular joint.
- The left common carotid artery begins arises from the arch of the aorta and ascends into the neck, posterior to the left sternoclavicular joint.
- Each common carotid artery ascends into the neck within the carotid sheath to the level of the superior border of the thyroid cartilage.
- Here it terminates by dividing into the internal and external carotid arteries.

# The Internal Carotid Artery
- This is the direct continuation of the common carotid artery and it has no branches in the neck.
- It supplies structures inside the skull.
- The internal carotid arteries are two of the four main arteries that supply blood to the brain.
- Each artery arises from the common carotid at the level of the superior border of the thyroid cartilage.
- It then passes superiorly, almost in a vertical plane, to enter the carotid canal in the petrous part of the temporal bone.
- A plexus of sympathetic fibres accompany it.
- During its course through the neck, the internal carotid artery lies on the longus capitis muscle and the sympathetic trunk.
- The vagus nerve (CN X) lies posterolateral to it.
- The internal carotid artery enters the middle cranial fossa beside the dorsum sellae of the sphenoid bone.
- Within the cranial cavity, the internal carotid artery and its branches supply the hypophysis cerebri (pituitary gland), the orbit, and most of the supratentorial part of the brain.

# The External Carotid Arteries
- This vessel begins at the bifurcation of the common carotid, at the level of the superior border of the thyroid cartilage.
- It supplies structures external to the skull.
- The external carotid artery runs posterosuperiorly to the region between the neck of the mandible and the lobule of the auricle.
- It terminates by dividing into two branches, the maxillary and superficial temporal arteries.
- The stems of most of the six branches of the external carotid artery are in the carotid triangle.

# The Superior Thyroid Artery
- This is the most inferior of the 3 anterior branches of the external carotid.
- It arises close to the origin of the vessel, just inferior to the greater horn of the hyoid.
- The superior thyroid artery runs anteroinferiorly, deep to the infrahyoid muscles and gives off the superior laryngeal artery. This artery pierces the thyrohyoid membrane in company with the internal laryngeal nerve and supplies the larynx.

# The Lingual Artery
- This arises from the external carotid artery as it lies on the middle constrictor muscle of the pharynx.
- It arches superoanteriorly, about 5 mm superior to the tip of the greater horn of the hyoid bone, and then passes deep to the hypoglossal nerve, the stylohyoid muscle, and the posterior belly of digastric muscle.
- It disappears deep to the hyoglossus muscle.
- At the anterior border of this muscle, it turns superiorly and ends by becoming the deep lingual artery.

# The Facial Artery
- This arises from the carotid artery either, in common with the lingual artery, or immediately superior to it.
- In the neck the facial artery gives off its important tonsillar branch and branches to the palate and submandibular gland.
- The facial artery then passes superiorly under the cover of the digastric and stylohyoid muscles and the angle of the mandible.
- It loops anteriorly and enters a deep groove in the submandibular gland.
- The facial artery hooks around the inferior border of the mandible and enters the face. Here the pulsation of this artery can be felt (anterior to the masseter muscle).

# The Ascending Pharyngeal Artery
- This is the 1st or 2nd branch of the external carotid artery.
- This small vessel ascends on the pharynx, deep to the internal carotid artery.
- It sends branches to the pharynx, prevertebral muscles, middle ear and meninges.

# The Occipital Artery
- This arises from the posterior surface of the external carotid near the level of the facial artery.
- It passes posteriorly along the inferior border of the posterior belly of digastric.
- It ends in the posterior part of the scalp.
- During its course, it is superficial to the internal carotid artery and three cranial nerves (CN IX, CN X and CN XI).

# The Posterior Auricular Artery
- This is a small posterior branch of the external carotid artery.
- It arises from it at the superior border of the posterior belly of the digastric muscle.
- It ascends posteriorly to the external acoustic meatus and supplies adjacent muscles, the parotid gland, the facial nerve, structures in the temporal bone, the auricle, and the scalp.
CME Category::Cardiology