| Suprahyoid muscles | |
|---|---|
 Muscles of the neck. Anterior view. Hyoid bone is white horizontal line near top. Infrahyoid muscles are below hyoid, whileSuprahyoid muscles are labeled above. | |
| Details | |
| Identifiers | |
| Latin | musculi suprahyoidei |
| TA98 | A04.2.03.001 |
| TA2 | 2159 |
| FMA | 71301 |
| Anatomical terms of muscle | |
Thesuprahyoid muscles are fourmuscles located above thehyoid bone in theneck. They are thedigastric,stylohyoid,geniohyoid, andmylohyoid muscles. They are allpharyngeal muscles, with the exception of the geniohyoid muscle. Thedigastric is uniquely named for its two bellies. Its posterior belly rises from themastoid process of thecranium and slopes downward and forward. The anterior belly arises from thedigastric fossa on the inner surface of themandibular body, which slopes downward and backward. The two bellies connect at theintermediate tendon. The intermediate tendon passes through a connective tissue loop attached to the hyoid bone.[1] Themylohyoid muscles are thin, flat muscles that form a sling inferior to the tongue supporting the floor of the mouth. Thegeniohyoids are short, narrow muscles that contact each other in the midline.[2] Thestylohyoids are long, thin muscles that are nearly parallel with the posterior belly of the digastric muscle.[2]
These four muscles have different actions, but in general assist in elevating thehyoid bone and widening theesophagus duringswallowing. When the two bellies of thedigastric contract, they pull upward on the hyoid bone; but if the hyoid is fixed from below, thedigastric assists in extreme opening of the mouth such as yawning or taking a large bite of an apple.[1] Themylohyoid elevates the hyoid bone, tenses the floor of the mouth. Thegeniohyoid pulls the hyoid bone anterosuperiorly, shortening the floor of the mouth and widening the pharynx during swallowing. Thestylohyoid elevates and retracts the hyoid bone, elongating the floor of the mouth during swallowing.[2]
| Muscle | Origin | Insertion | Innervation |
|---|---|---|---|
| Digastric (anterior belly) | Digastric fossa of Mandible | Intermediate Tendon | Mylohyoid nerve - branch of CN V3 (Mandibular division of Trigeminal nerve) |
| Digastric (posterior belly) | Mastoid notch | Intermediate Tendon | Facial nerve (CN VII) |
| Geniohyoid | Inferiormental spine ofsymphysis menti | Hyoid | Cervical spinal nerve 1 via the hypoglossal nerve (CN XII) |
| Stylohyoid | Temporal styloid process | Hyoid | Facial nerve (CN VII) |
| Mylohyoid | Mylohyoid line of mandible | Hyoid | Mylohyoid nerve - branch of CN V3 (Mandibular division of Trigeminal nerve - CN V) |
