Suprahyoid muscles

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Suprahyoid muscles
Suprahyoid muscles.png
Muscles of the neck. Anterior view.
Hyoid bone is white horizontal line near top.
Infrahyoid muscles are below hyoid, while Suprahyoid muscles are labeled above.
Details
Identifiers
Latin Musculi suprahyoidei
TA A04.2.03.001
FMA 71301
Anatomical terms of muscle

The suprahyoid muscles are four muscles located above the hyoid bone in the neck. They are the digastric, stylohyoid, geniohyoid, and mylohyoid muscles. They are all pharyngeal muscles, with the exception of the geniohyoid muscle. The digastric is uniquely named for its two bellies. Its posterior belly rises from the mastoid process of the cranium and slopes downward and forward. The anterior belly arises from the mastoid notch on the inner surface of the mandibular body, which slopes downward and backward. The two bellies connect at the intermediate tendon. The intermediate tendon passes through a connective tissue loop attached to the hyoid bone.[1] The mylohyoid muscles are thin, flat muscles that form a sling inferior to the tongue supporting the floor of the mouth. The geniohyoids are short, narrow muscles that contact each other in the midline.[2] The stylohyoids are long, thin muscles that are nearly parallel with the posterior belly of the digastric muscle.[2]

Function[edit]

These four muscles have different actions, but in general assist in elevating the hyoid bone and widening the esophagus during swallowing. When the two bellies of the digastric contract, they pull upward on the hyoid bone; but if the hyoid is fixed from below, the digastric assists in extreme opening of the mouth such as yawning or taking a large bite of an apple.[1] The mylohyoid elevates the hyoid bone, tenses the floor of the mouth. The Geniohyoid pulls the hyoid bone anterosuperiorly, shortening the floor of the mouth and widening the pharynx during swallowing. The Stylohyoid 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
Geniohyoid Inferior mental spine of Symphysis menti Hyoid C1 via the hypoglossal nerve (XII)
Stylohyoid Temporal styloid process Hyoid Facial nerve
Mylohyoid Mylohyoid line of mandible Hyoid Mylohyoid nerve - branch of CN V3 (Mandibular division of Trigeminal nerve)

See also[edit]

References[edit]

  1. ^ a b Saladin, Kenneth (2015). Anatomy & Physiology: The Unity of Form and Function (7th ed.). New York, NY: McGraw Hill Education. p. 324. ISBN 978-0-07-340371-7. 
  2. ^ a b c "Extrinsic Muscles" (PDF). Phoniatrics-uep. Retrieved 3 Dec 2015.