Anterior belly of digastric

The anterior belly of the digastric (Latin: venter anterior musculi digastrici) is one of two bellies composing the digastric muscle. The digastric is one of the muscles of the neck, and its other belly is known as the posterior belly. As the digastric muscle is located above the hyoid bone, it is classified as the suprahyoid neck muscle. It also belongs to the anterior neck muscles. The anterior belly is smaller than the posterior, and it develops from the first pharyngeal arch.

Origin

The anterior belly of the digastric muscle originates from the digastric fossa located on the inner surface of the mandible.

Insertion

From the origin site, the anterior belly of the digastric passes downward and backward. Fibers of this belly form the intermediate tendon that attaches to the hyoid bone.

Action

Upon contraction, the anterior belly of the digastric muscle elevates the hyoid bone or depresses the lower jaw.

Innervation

The anterior belly of the digastric is innervated by the mylohyoid nerve, a branch of the inferior alveolar nerve. The latter nerve arises from the mandibular division of the trigeminal nerve (CN V3).

Blood supply

The anterior belly of the digastric muscle receives arterial blood supply from the facial artery - a branch of the external carotid artery.