digastric muscle

Introduction

One of the suprahyoid group of muscles, consisting of 2 bellies joined by a central tendon that passes through a loop of fascia connected to the body of the hyoid bone.

Origin

• by the posterior belly from the diastric groove medial to the mastoid process

Insertion

• by the anterior belly into the lower border of the mandible near the midline

Action

elevated the hyoid bone when the mandible is fixed

Innervation

• posterior belly: facial nerve (CN VII)
• anterior belly: nerve to the mylohyoid from the mandibular division of the trigeminal nerve (CN V)

Course

The posterior belly passes deep to the angle of the mandible & superficial to the internal carotid artery, external carotid artery, internal jugular vein, & cranial nerves X, XI & XII.

More general terms

• skeletal muscle (voluntary muscle)