Master Pharyngeal Arch Derivatives: 3rd Arch

The hyoid is a horseshoe-shaped bone that is located in the anterior neck at the level of C3. It is located between the mandible and the thyroid cartilage. The second pharyngeal arch gives rise to the lesser horn of the hyoid, while the third pharyngeal arch gives rise to the greater horn of the hyoid.

The stylopharyngeus originates from the styloid process of the temporal bone and inserts on the thyroid cartilage. It acts to elevate the pharynx during swallowing and speech. Since this muscle develops from the third pharyngeal arch, it is innervated by CN IX (glossopharyngeal).

CN IX is also known as the glossopharyngeal nerve. It is a motor and sensory nerve that has various functions, including swallowing and taste sensation for the posterior one-third of the tongue.

The third pharyngeal arch is tightly associated with the third aortic arch. This aortic arch develops into the common carotid artery and proximal part of the internal carotid artery. The right common carotid arises from the brachiocephalic artery. The left common carotid arises from the aortic arch.

The third pair of pharyngeal arch arteries develops into the common carotid artery and proximal part of the internal carotid artery. The internal carotid arteries arise from the common carotid arteries.