Origin
Mastoid notch of the temporal bone.
Insertion
It inserts into the mandible – in the digastric fossa.
Blood supply
Anterior belly – facial artery, inferior alveolar artery.
Posterior belly – occipital artery.
Nerve supply
Anterior belly – trigeminal nerve.
Posterior belly – facial nerve.
Action
It helps to elevate the hyoid bone which helps to control the esophagus and pharynx during swallowing and speaking. It helps to open the mouth.
Disease/Injury
Nasal blockage, sinus problem, deviated nasal septum and nasal polyp may put stress on the digastric muscle. In such cases you breathe through mouth and keep the mouth open, which leads to pain.
Muscle exercise
You can do isometric head lift exercise. Lie on your back with a pillow underneath your head. Lift your head and look at the toes for a minute. Then relax and repeat the exercise thrice.
Interesting facts
If there is more tension in the digastric muscle, it becomes difficult for singers to sing with the high notes.
