![]() The course of the styloglossus muscles attaches the pharyngeal and submandibular spaces, forming the buccopharyngeal gap between the middle and superior constrictor muscles of the pharynx. Damage of the hypoglossal nerve causes ipsilateral deviation of the tongue, i.e., the tongue will turn to the side of the lesion or injury. On examination, patients are introduced to protruding the tongue. Thus, it is possible to evaluate the function of the hypoglossal nerve by testing the movements of the tongue. Styloglossus action Clinical SignificanceĪs an extrinsic muscle of the tongue, the styloglossus muscles are innervated by the hypoglossal (XII) nerve. Functioning bilaterally (both styloglossus muscles contracting simultaneously) they also aid in retracting the tongue The styloglossus pulls up the sides of the tongue to create a trough for swallowing. The lingual nerve, a branch of the mandibular branch of the trigeminal (V) nerve, supplies somatic sensation to the anterior two-thirds of the tongue. Taste sense to the anterior two-thirds of the tongue is supplied through the chorda tympani branch of the facial (VII) nerve and the glossopharyngeal (IX) nerve to the posterior one-third the glossopharyngeal nerve also gives somatic sensation to the posterior one-third of the tongue. Impairment to the hypoglossal nerve influences ipsilateral deviation of the tongue, i.e., damage to the left hypoglossal nerve will induce deviation of the tongue to the left side. The hypoglossal nerve traverses superficially to the hyoglossus muscle. The intrinsic and extrinsic musculature of the tongue is held by the 12th cranial nerve, the hypoglossal nerve, excluding the palatoglossus muscle, which is innervated by the 10th cranial nerve, the vagus nerve. ![]() Dorsal lingual arteries supply the bottom of the tongue, whereas deep lingual arteries supply the body of the tongue. The lingual artery is a direct branch of the external carotid artery it carries off from the external carotid at the level of the greater horn of the hyoid bone.Īfter this, the lingual artery travels between the hyoglossus (superficial) and middle pharyngeal constrictor (deep) to provide blood to the tongue. The styloglossus muscles acquire their blood supply from the sublingual branches of the lingual artery. Following mastication, these movements promote the passage of the food bolus toward the oropharynx. The styloglossus muscle’s role is to retract and elevate the tongue in a posterior and also superior manner. These smaller bundles approach between the inferior longitudinal intrinsic muscles of the tongue and the genioglossus muscle and eventually insert into the lingual septum. The posterior bundles of the styloglossus muscles are divided into approximately 10 smaller bundles of fibers that enter the tongue. Anteriorly, the bundles run bilaterally and assemble at the midline of the floor of the tongue, forming an arch. The fibers of the styloglossus muscles can be divided into anterior and posterior bundles. External and internal fibers of the styloglossus muscles also fuse with pieces of the superior pharyngeal constrictor muscle and the palatoglossus muscle, respectively, with three bundles traveling anteriorly towards the apex of the tongue and an inferior longitudinal bundle connecting the inferior fibers of the genioglossus muscle. The styloglossus muscles insert into the lateral aspect of the tongue, namely into the fibers of the intrinsic longitudinal muscles and between the two portions of the hyoglossus muscle. It diverges upon the side of the tongue near the dorsal surface of the tongue, blending with the fibers of the longitudinal inferior muscle anterior to the hyoglossus muscle. It originates from (the anterior and lateral surfaces of) the styloid process of the temporal bone near its apex, and from the stylomandibular ligament. ![]() The paired styloglossus muscles also function to retract and elevate the tongue in a posterior and superior direction. The styloglossus muscles induce the lateral margins of the tongue to curve upwards, forming a furrow to permit swallowing following the mastication of food particles. ![]() It coordinates with the additional extrinsic muscles of the tongue, including the hyoglossus muscles, the genioglossus muscle, and the palatoglossus muscle, to make the various movements of the tongue. ![]() The styloglossus muscles are paired with the extrinsic muscle of the tongue. The tongue is also essential in the exhibition of speech and essential for employing the sense of taste. The human tongue is an organ that helps the process of digestion by facilitating the manipulation and movement of food particles during mastication and swallowing. ![]()
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