Muscles of the hyoid region

Muscles of the hyoid region are-

1. Mylo-hyoideus
2. Stylo-hyoideus
3. Genio-hyoideus
4. Occipito-hyoideus
5. Kerato-hyoideus
6. Hyoideus transversus
7. Sterno-thyro-hyoideus
8. Omo-hyoideus

Mylo-hyoideus

• The two muscles form a sling for the tongue.
• Origin: Medial face of the mandible, below the alveolar bone.
• Insertion:Medial fibrous raphe and lingual process of the hyoid bone.
• Action: To raise the tongue and hyoid bone.
• Blood supply: Sublingual artery.
• Nerve supply: Mandibular nerve.

Stylo-hyoideus

• Origin:The muscular angle of great cornu of hyoid bone.
• Insertion: Lateral extremity of body of hyoid bone.
• Action: To draw the tongue and hyoid bone upwards and backwards.
• Blood supply:  a branch from external maxillary artery.
• Nerve supply: Facial nerve (styloid branch).

Genio-hyoideus

• Origin:The fossa on the medial face of the ramus of mandible close to the symphysis.
• Insertion: Body of hyoid.
• Action: To draw the tongue and hyoid forward.
• Blood supply: Lingual and sublingual artery.
• Nerve supply: Hypoglossal nerve.

Occipito-hyoideus

• This muscle is a thick triangular muscle, which fills the space between the proximal extremity of the great cornu and the paramastoid process.
• Origin:Paramastoid process.
• Insertion:The posterior border of the muscular angle of the stylohyoid.
• Action:To draw the great cornu backward.
• Blood supply: Posterior auricular artery.
• Nerve supply: Facial nerve.

Kerato-hyoideus

• This is a small triangular flat muscle fills up the angular space between the small and thyroid cornu. It is covered mostly by the hyo-pharyngeus and partly by hyo-glossus.
• Origin: Posterior border of small cornu.
• Insertion:Dorsal border of the thyroid cornu.
• Action:To raise the larynx.
• Blood supply: Lingual artery.
• Nerve supply: Glosso-pharyngeal nerve.

Hyoideus transversus

• A small-unpaired muscle situated between the two small cornua, enclosed by mucous membrane. It raises the root of the tongue.
• Blood supply: Lingual artery.
• Nerve supply: Glosso-pharyngeal nerve.

Sterno-thyro-hyoideus

• This is a long, slender muscle situated on the ventral face of the trachea.
• Origin:Manubrium sterni.
  • The two side muscles are very close together at their origin and cover trachea at the lower third of the neck. About the middle of the neck, each muscles divide into two bands-the thyroid and hyoid bands which diverge from those of the opposite side from the upper third of the neck. Hence in the upper third of the neck, the ventral face of the trachea is not covered by any muscle. The thyroid band is the larger and the lateral of the two bands.
• Insertion:Thyroid band is inserted to the thyroid cartilage of the larynx and the hyoid band to the body of the hyoid and lingual process.
• Action:To depress the hyoid, larynx, and tongue during deglutition .
• Blood supply: a branch from carotid artery.
• Nerve supply: First and second cervical spinal nerves .

Omo-hyoideus

• This is small triangular muscle extending from the neck at its ventro-lateral aspect in an oblique direction upward and forward to the hyoid bone.
• Origin:Transverse processes of the third and fourth cervical vertebrae.
  • This muscle passes under the deep face of the brachio-cephalicus and sterno-mastoideus obliquely forwards and inwards laterally over the sterno-mastoideus or passes through the latter and passes forwards in company with the hyoid band of the sterno-thyro-hyoideus.
• Insertion:Body of the hyoid bone.
• Action:To retract the hyoid and root of the tongue.
• Blood supply: a branch from  carotid artery.
• Nerve supply: Second cervical spinal nerve.