Stylopharyngeus muscle

The stylopharyngeus muscle is a slender, longitudinal muscle of the pharynx that plays an essential role in elevating the pharynx and larynx during swallowing and speech.

Origin

The stylopharyngeus muscle arises from the medial surface of the styloid process of the temporal bone and descends between the superior and middle pharyngeal constrictor muscles, accompanied by the glossopharyngeal nerve (cranial nerve IX).

Insertion

The stylopharyngeus muscle fibres spread out within the pharyngeal wall, some fibres blending with those of the palatopharyngeus, while others attach to the posterior border of the thyroid cartilage.

Innervation

The stylopharyngeus is unique among the pharyngeal muscles in that it is the only one innervated by the glossopharyngeal nerve (CN IX), whereas all other pharyngeal muscles receive motor supply from the vagus nerve via the pharyngeal plexus. The glossopharyngeal nerve descends along the lateral surface of the stylopharyngeus, then curves forward from behind it it to reach the posterior aspect of the tongue,

Actions

Functionally, the stylopharyngeus muscle elevates and widens the pharynx during swallowing, facilitating the passage of the food bolus, and also assists in raising the larynx during phonation.