Suprahyoid Muscles

Question 1

Digastric

Answer 1

Origin:

• anterior belly: digastric fossa of mandible
• posterior belly: mastoid notch of temporal bone

Insertion: intermediate tendon attached to body of hyoid

Innervation:

• anterior belly: nerve to mylohyoid
• posterior belly: facial nerve

Blood Supply:

• anterior belly: branches of submental artery
• posterior belly: muscular branches of posterior auricular artery and muscular branches of occipital artery

Action: raises hyoid bone and base of tongue, steadies hyoid bone, and opens mouth by lowering mandible

Question 2

Mylohyoid

Answer 2

Origin: mylohyoid line of mandible

Insertion: median raphe and body of hyoid bone

Innervation: nerve to mylohyoid nerve (branch of trigeminal nerve)

Blood Supply: sublingual branch of lingual artery and submental branch of facial artery

Action: elevates hyoid bone, base of tongue, floor of mouth, and depresses mandible

Question 3

Geniohyoid

Answer 3

Origin: inferior genial tubercle on back of symphysis of mandible

Insertion: anterior surface of body of hyoid bone

Innervation: branch of C1 through hypoglossal nerve (CN XII)

Blood Supply: sublingual branch of lingual artery

Action: elevates hyoid bone and depresses mandible

Question 4

Stylohyoid

Answer 4

Origin: posterior border of styloid process

Insertion: body of hyoid bone at junction with greater horn

Innervation: facial nerve

Blood Supply: muscular branches of facial artery and muscular branches of occipital artery

Action: elevates hyoid bone and base of tongue