- Skeletal system
- Head muscles
- Superficial neck muscles
- Scalene muscles
- Suprahyoid muscles
- Infrahyoid muscles
- Prevertebral muscles
- Suboccipital muscles
- Muscles of upper limb
- Thoracic muscles
- Muscles of back
- Muscles of lower limb
- Blood vessels
- Respiratory system
- Digestive system
- Endocrine glands
- Nervous system
- Lymphatic system
- Female reproductive system
- Male reproductive system
The omohyoid (Latin: musculus omohyoideus) is a slender neck muscle that, together with the sternohyoid, sternothyroid and thyrohyoid muscles, is classified as the infrahyoid muscle. It is located in the anterior aspect of the neck. Therefore, it also belongs to the anterior neck muscles group. The omohyoid depresses the hyoid bone. This muscle is composed of two bellies - inferior and superior - connected by an intermediate tendon.
Inferior belly - upper margin of scapula
Superior belly - intermediate tendon
Inferior belly - intermediate tendon
Superior belly - body of hyoid bone
Depresses hyoid bone and larynx
Retracts hyoid bone
Tenses carotid sheath
|Innervation||Anterior rami of 1st to 3rd cervical spinal nerves via ansa cervicalis|
|Blood supply||Superior and inferior thyroid arteries|
The inferior belly of the omohyoid originates from the upper margin of the scapula, and the superior belly originates from the intermediate tendon.
The inferior belly of the omohyoid inserts in the intermediate tendon, while the superior belly inserts on the inferior aspect of the body of the hyoid bone.
Upon activation, the omohyoid muscle depresses the hyoid bone and larynx. It also pulls the hyoid bone backward and to the side (retracts the hyoid bone). This muscle elevates the scapula. The intermediate tendon fuse together with the tissues of the carotid sheath. Therefore, the omohyoid also tenses the carotid sheath.
The omohyoid is innervated by the anterior rami of the 1st to 3rd cervical spinal nerves (C1 - C3) via the ansa cervicalis arising from the cervical plexus.
The omohyoid receives arterial blood supply from the superior and inferior thyroid arteries. The first one is a branch of the external carotid artery, while the second arises from the thyrocervical trunk.