Digastric: The digastric muscle is positioned in the neck, beneath the jaw. It occupies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. This muscle assists in opening and closing the jaw.
Origin: Anterior belly – digastric fossa of the mandible.
Posterior belly – mastoid process of the temporal bone.
Insertion: The two bellies are united by an intermediate tendon, which is connected to the hyoid bone via a fibrous sling.
Nerve Supply: Anterior belly – the mandibular division (V3) of the trigeminal (CN V) through the mylohyoid nerve.
Posterior belly – facial nerve (CN VII).
Blood Supply: Anterior belly – the Submental branch of the facial artery
Posterior belly – occipital artery
Function: The digastric muscle depresses the mandible and elevates the hyoid bone.
Neck Muscles: Origin, Insertion, Action & Nerve Supply