Digastric – posterior belly

Anatomy

Origin:
Mastoid notch on medial side of mastoid process of temporal bone.

Insertion:
Intermediate tendon between the two bellies which itself attaches to the body of the hyoid bone.

Key Relations:
-Is one of the suprahyoid muscles lying in the anterior triangle of the neck.
-Forms inferoposterior boundary of submandibular triangle.
-Forms superior boundary of carotid triangle.
-Anteromedial to the posterior belly of digastric is another suprahyoid muscle geniohyoid.

Functions

-Elevates hyoid bone.
-Depresses the mandible.

e.g. opens mouth and aids swallowing (deglutition)..

Supply

Nerve Supply:
Facial nerve (CN 7)

Blood Supply:
–Posterior auricular artery
–Occipital artery.

Clinical

Relation to triangles of the neck – anterior triangles of the neck and posterior triangles of the neck.

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