Omohyoid Muscle

Description

Running obliquely across the anterior cervical region, the omohyoid muscle is presented as a two-bellied infrahyoid strap muscle with an inferior belly arising from the superior border of the scapula near the suprascapular notch and a superior belly inserting on the inferior border of the hyoid bone. An intermediate tendon interrupts the muscle near the lateral neck, where it is tethered to the clavicle by a fascial sling and lies deep to the sternocleidomastoid. Medially, the superior belly approaches the sternohyoid and thyrohyoid in the infrahyoid compartment; laterally, it crosses toward the carotid sheath, where the common carotid artery and internal jugular vein run vertically. Clear landmarks. Clinical relevance centers on the omohyoid as a boundary and a guide. During neck dissection, its superior belly helps define levels III and IV lymph node basins, and its relationship to the carotid sheath assists orientation when tracing the internal jugular vein, the vagus nerve, and the ansa cervicalis branch that typically innervates the muscle. Surgeons also watch the intermediate tendon and fascial sling because tethering can distort soft tissue planes and, in thin patients, the muscle can be mistaken for a fibrous band when approaching the internal jugular vein for central venous access. Teaching use is straightforward: this plate supports head and neck anatomy labs, otolaryngology and endocrine surgery courses, and atlas figures that need a correct infrahyoid layout from the hyoid to the shoulder girdle. It also suits procedural training materials that explain cervical triangles and safe dissection planes around the carotid sheath and jugular venous system. Anatomical accuracy verified by SciePro's Medical Advisory Board.