Omohyoid

From Ganfyd

Jump to: navigation, search

The omohyoid is a muscle of the neck.

Omohyoid
Omohyoid.GIF
Lateral neck dissection including omohyoid
System: Muscle
Function: Depresses hyoid bone and larynx
Origin: Upper border of scapula
Branches:
Insertion: Hyoid bone
Arterial supply:
Venous drainage:
Lymphatic drainage:
Innervation: Ansa cervicalis (C1 - C3)
Vertebral levels:
Search for Omohyoid in Gray's.

Contents

Shape

The omohyoid consists of two separate bellies of muscle which are united by a central tendon.

Inferior belly

From its origin, the inferior belly forms a narrow fascicle which travels medially and slightly superiorly, bound to the clavicle by a fibrous expansion. It passes behind sternocleidomastoid, where it becomes tendinous and bends sharply superiorly.

Central tendon

The central tendon begins posteriorly posterior to sternocleidomastoid. It is held in place by a sheath of the deep cervical fascia, which is attached to the clavicle and first rib. The tendon ends in the superior belly.

Superior belly

The superior belly passes vertically, ascending the neck adjacent to the lateral border of sternohyoid and inserting just lateral to its insertion.

Actions

  • Depresses the hyoid bone and pulls it laterally
  • Through this action, depresses the larynx

Origin

Insertion

Nerve Supply

Clinical Relevance

Variations

  • The central tendon is highly variable in length and form
  • May arise from the suprascapular ligament and adjacent scapula
  • Attachment to the scapula varies in length
  • May be doubled
  • May be absent
  • May originate from the clavicle
  • Either belly may be absent or doubled
Personal tools