Suprahyoid muscles

Question 1

Outline

Answer 1

one end of all these muscles is attached to the horseshoe-shaped hyoid bone which lies suspended in soft tissue beneath the mandible, in the throat. they then all lie above this bone, as opposed to a separate group of muscles lying beneath the bone called infra hyoid muscles

Question 2

The suprahyoid muscles

Answer 2

are responsible for mouth opening + swallowing actions
one group of these muscles lie infront of the hyoid bone + others behind, producing anterior + posterior groups. (the anterior group is of relevance to dental nurse)

Question 3

Nerve supply

Answer 3

the anterior digastric + mylohyoid muscles are innervated by the motor branch of the trigeminal nerve (fifth cranial nerve) whilst the geniohyoid is innervated by the hypoglossal nerve (12th cranial nerve)

Question 4

1. Anterior digastric

Answer 4

point of origin- hyoid bone
point of insertion - inner surface of mental symphysis of mandible
action - helps to lift hyoid bone + larynx during swallowing, pulls mandible down to open mouth

Question 5

2. Mylohyoid

Answer 5

point of origin- mylohoid line of the inner surface of mandible, fusing in the midline to form floor of mouth
point of insertion- hyoid bone
action- lift hyoid bone + larynx during swallowing + open the mouth

Question 6

3. Geniohyoid

Answer 6

point of origin - genial tubercles on inner surface of mandible
point of insertion - hyoid bone
-action - lift hyoid bone + larynx during swallowing + open the mouth