Infrahyoid muscles

Infrahyoid muscles
Muscles of the neck seen from the front. The infrahyoid muscles are coloured in violet.
Details
Nerve	Ansa cervicalis (except thyrohyoid muscle)
Actions	Depress the hyoid bone
Identifiers
Latin	musculi infrahyoidei
TA98	A04.2.04.001
TA2	2167
FMA	71298
Anatomical terms of muscle [ edit on Wikidata]

The infrahyoid muscles, or strap muscles, are a group of four pairs of muscles in the anterior (frontal) part of the neck. ^[1] The four infrahyoid muscles are the sternohyoid, sternothyroid, thyrohyoid and omohyoid muscles. ^[1]

Excluding the sternothyroid, the infrahyoid muscles either originate from or insert on to the hyoid bone. ^[2]

The term infrahyoid refers to the region below the hyoid bone, while the term strap muscles refers to the long, and flat muscle shapes which resembles a strap. The stylopharyngeus muscle is considered by many to be one of the strap muscles,^{[ citation needed ]} but is not an infrahyoid muscle.

Individual muscles

The origin, insertion and innervation of the individual muscles: ^[3]

Muscle	Origin	Insertion	Innervation
Sternohyoid	Posterior surface of manubrium sterni, adjoining parts of clavicle and the posterior sternoclavicular ligament	Medial part of lower border of hyoid bone	Ansa cervicalis
Sternothyroid	Posterior surface of manubrium sterni and adjoining part of first costal cartilage	Oblique line of thyroid cartilage	Ansa cervicalis
Thyrohyoid	Oblique line of the thyroid cartilage	Lower border of the body and the greater cornu of the hyoid bone	Cervical spinal nerve 1 via the hypoglossal nerve
Omohyoid (superior belly)	Intermediate tendon	Hyoid bone	Superior root of ansa cervicalis (C1)
Omohyoid (inferior belly)	Superior border of scapula	Intermediate tendon	Ansa cervicalis (C1-C3)

Nerve supply

All of the infrahyoid muscles are innervated by the ansa cervicalis from the cervical plexus (C1-C3) ^{[4] [5]} except the thyrohyoid muscle, which is innervated by fibers only from the first cervical spinal nerve travelling with the hypoglossal nerve. ^[1]

Function

The infrahyoid muscles function to elevate and depress the hyoid bone and larynx during swallowing and speech. ^[6] This moves the larynx as one unit. ^[7]

See also

• Muscular triangle
• Suprahyoid muscles

References

1. McHanwell, Steve; Watson, Charles (1 January 2009). "Localization of Motoneurons in the Spinal Cord" . The Spinal Cord: 94–114. doi:10.1016/B978-0-12-374247-6.50011-0. ISBN   9780123742476.
2. KenHub. "Infrahyoid muscles" . Retrieved 24 May 2019.
3. Ellis, Harold; Susan Standring; Gray, Henry David (2005). Gray's anatomy: the anatomical basis of clinical practice. St. Louis, Mo: Elsevier Churchill Livingstone. pp.  538–539. ISBN   0-443-07168-3.
4. Cesmebasi, Alper (1 January 2015), Tubbs, R. Shane; Rizk, Elias; Shoja, Mohammadali M.; Loukas, Marios (eds.), "Chapter 31 - Anatomy of the Cervical Plexus and Its Branches" , Nerves and Nerve Injuries, San Diego: Academic Press, pp. 441–449, doi:10.1016/b978-0-12-410390-0.00032-9, ISBN   978-0-12-410390-0
5. Kayalioglu, Gulgun (1 January 2009), Watson, Charles; Paxinos, George; Kayalioglu, Gulgun (eds.), "Chapter 4 - The Spinal Nerves" , The Spinal Cord, San Diego: Academic Press, pp. 37–56, doi:10.1016/b978-0-12-374247-6.50008-0, ISBN   978-0-12-374247-6
6. Merea, Valeria Silva; Pitman, Michael J. (1 January 2019), Chhetri, Dinesh K.; Dewan, Karuna (eds.), "Chapter 5 - Anatomy and Physiology of the Upper Esophageal Sphincter" , Dysphagia Evaluation and Management in Otolaryngology, Elsevier, pp. 29–34, doi:10.1016/b978-0-323-56930-9.00005-x, ISBN   978-0-323-56930-9, S2CID   80855923
7. Feinstein, Aaron J.; Dewan, Karuna (1 January 2019), Chhetri, Dinesh K.; Dewan, Karuna (eds.), "Chapter 4 - Larynx" , Dysphagia Evaluation and Management in Otolaryngology, Elsevier, pp. 23–28, doi:10.1016/b978-0-323-56930-9.00004-8, ISBN   978-0-323-56930-9