Digastric muscle
From Freepedia
The digastric muscle (named digastric as it has two bellies) is a small muscle located under the jaw. The two bellies are separated by an intermediate tendon, which runs through a sling on the side of the hyoid bone.
The posterior belly is attached to the mastoid process of the temporal bone, and the anterior belly is attached to the front of the mandible.
The two bellies of the digastric muscle have different embryological origin, and are supplied by different cranial nerves. The posterior belly is supplied by a branch of the facial nerve, and the anterior body supplied by the trigeminal.
When the digastric muscle contracts, it acts to elevate the hyoid bone. If the hyoid is being held in place (by the infrahyoid muscles), it will tend to depress the mandible (open the mouth).
| Muscles of the anterolateral region of the neck | |
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The lateral cervical muscles: Sternocleidomastoid muscle | Trapezius muscle The suprahyoid muscles: Stylohyoid muscle | Digastric muscle | Geniohyoid muscle | Mylohyoid muscle The infrahyoid muscles: Omohyoid muscle | Sternohyoid muscle | Sternothyroid muscle | Thyrohyoid muscle The vertebral muscles -- anterior : Longus capitis muscle | Longus colli muscle | Rectus capitis anterior muscle | Rectus capitis lateralis muscle | lateral: Scalenus anterior muscle | Scalenus medius muscle | Scalenus posterior muscle | |
