Anatomy, Head and Neck, Posterior Auricular Artery

The word "auricle" translates to a structure that looks similar to an ear. Cartilage comprises the entire auricular structure of the ear. The function of the ear is to funnel in sound, and then the sound is converted into various signals in the brain. Without the ear, sounds will be less amplified and seem to have lower volume.

The ear receives the majority of its blood from a branch of the external carotid artery. The external carotid artery gives off a branch called the posterior auricular artery. The meaning of the "posterior auricular" is an area posterior to the auricular structure; this is the exact territory of the posterior auricular artery's perfusion. The posterior auricular artery is also the main blood supply to the external ear.

The posterior auricular artery is a smaller muscular artery that branches from the external carotid artery. This artery travels to the region posterior to the ear. The function of the posterior auricular artery is to perfuse the scalp and the ear.[1] The minor function of the posterior auricular artery is to provide collateral blood flow via the anastomoses that form with the superior temporal artery, the parietal artery, and the anterior auricular artery. The anastomoses with the superior temporal artery provide collateral blood supply to the temporal region of the head. The connection between the posterior auricular artery and the anterior auricular artery provides complete perfusion of the auricular part (cartilage part of the ear) of the ear. The connection between the posterior auricular artery and the parietal artery provides additional blood to the parietal region of the skull.

During embryology, the arteries in the face, neck, and chest form from the aortic arches. The aortic arches will form around the same time as the formation brachial apparatus. The third aortic arch will develop into the common carotid artery. The common carotid artery will ascend laterally along the face, neck, and head. At the level of cervical vertebra four, the common carotid artery will bifurcate into the external carotid artery and internal carotid artery. The external carotid artery is responsible for perfusing the face and head. One of the branches that come off the external carotid artery is the posterior auricular artery. The external carotid artery branches into the posterior auricular artery at the level of the angle of the mandible. The posterior artery will then ascend towards the region posterior to the ear.

The posterior auricular artery will ascend towards the posterior side of the ear. The posterior auricular artery then perfuses the majority of the ear and the posterior region of the scalp. The posterior auricular artery will give off small auricular branches that perfuse the ear. Another branch that comes from the posterior auricular artery is the stylomastoid artery. The stylomastoid artery will perfuse the styloid process of the temporal bone, the mastoid process of the temporal bone, and the facial nerve. The facial nerve receives blood from the stylomastoid artery as it exits the stylomastoid foramen.[2][3] 

The posterior auricular artery forms anastomoses that will provide collateral blood flow to other regions on the face and head. Three main anastomoses form with the superior temporal artery, the parietal artery, and the anterior auricular artery. 

The lymph drainage from the scalp near the ear and the ear itself is towards the posterior auricular lymph nodes. The lymph fluid will eventually drain into the main circulation via the right lymphatic duct and the thoracic duct. The right ear will drain towards the right lymphatic duct. While the left ear drains toward the thoracic duct.[4]

The posterior auricular artery perfuses the majority of the ear and the scalp posterior to the ear. This perfusion region will also supply blood to the greater auricular nerve (C2, C3 spinal roots) and the lesser occipital nerve (C2 spinal roots). The facial nerve also receives perfusion from the posterior auricular artery at the stylomastoid foramen opening.