The stylopharyngeus is a muscle in the head that stretches between the

temporal styloid process The temporal styloid process is a slender bony process of the temporal bone extending downward and forward from the undersurface of the temporal bone just below the ear. The styloid process gives attachments to several muscles, and ligaments. Stru ...

and the

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...

Structure

The stylopharyngeus is a long, slender muscle, cylindrical above, flattened below. It arises from the medial side of the base of the

, passes downward along the side of the

between the superior pharyngeal constrictor and the middle pharyngeal constrictor, and spreads out beneath the mucous membrane. Some of its fibers are lost in the constrictor muscles while others, joining the palatopharyngeus muscle, are inserted into the posterior border of the

thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the ''laryngeal skeleton'', the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilage ...

. The

glossopharyngeal nerve The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve. ...

runs on the lateral side of this muscle, and crosses over it to reach the tongue.

Nerve supply

The stylopharyngeus is the only muscle in the pharynx innervated by the

(CN IX) via branchial motor neurons with their cell bodies in the rostral part of the nucleus ambiguus.

Development

Embryological origin is the third

pharyngeal arch The pharyngeal arches, also known as visceral arches'','' are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arche ...

Function

The stylopharyngeus: *elevates the

larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

*elevates the

*dilates the pharynx to permit the passage of a large food bolus, thereby facilitating swallowing

Additional images

File:Epiglotic cartilage.jpg, Stylopharyngeus muscle. File:Gray141.png, Left temporal bone. Inferior surface. File:Gray950.png, The cartilages of the larynx. Posterior view. File:Gray957.png, Side view of the larynx, showing muscular attachments. File:Gray1019.png, Extrinsic muscles of the tongue. Left side. File:Gray1031.png, Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves. File:Slide9aaa.JPG, Stylopharyngeus muscle File:Slide16aaa.JPG, Stylopharyngeus muscle File:Slide3ggg.JPG, Stylopharyngeus muscle File:Slide8hhh.JPG, Stylopharyngeus muscle

References