Muscles - Suprahyoids

Question 1

Where are the suprahyoid muscles? How many are there?

Answer 1

These are four muscles located above the hyoid.

Question 2

What is the function of these muscles?

Answer 2

Elevate the hyoid during swallowing.

Question 3

Arterial supply to these muscles?

Answer 3

Occipital + lingual - branches of the facial artery.

Question 4

What are the different suprahyoid muscles?

Answer 4

1) Stylohyoid
2) Digastric
3) Mylohyoid
4) Geniohyoid

Question 5

Stylohyoid

Answer 5

A thin muscular strip located superiorly to the posterior belly of the digastric muscle.

Origin - styloid process of the temporal bone.

Insertion - lateral aspect of the hyoid bone

Action - Initiates swallowing - pulling the hyoid posteriorly and superiorly

Innervation - Stylohyoid branch of the facial nerve - arises proximally to the parotid gland.

Question 6

Digastric

Answer 6

Comprised of two muscular bellies than converge into one tendon.

Origin (anterior belly) - digastric fossa of mandible

Origin (posterior belly) - mastoid process of temporal bone

Insertion - hyoid bone

Action - depresses the mandible and elevates the hyoid

Innervation (anterior belly) - inferior alveolar nerve, a branch of the mandibular nerve.

Innervation (posterior belly) - digastric branch of the facial nerve

Question 7

Mylohyoid

Answer 7

A broad, triangular shaped muscle. Forms the floor of the oral cavity and supports the floor of the mouth.

Origin - mylohyoid line of the mandible

Insertion - hyoid bone

Action - elevates the hyoid bone and the floor of the mouth

Innervation - Inferior alveolar nerve, a branch of the mandibular nerve

Question 8

Geniohyoid

Answer 8

Located close to the midline of the neck, deep to the mylohyoid muscle.

Origin - inferior mental spine of the mandible

Insertion - travels inferior and posteriorly to insert onto the hyoid bone.

Action - depresses the mandible and elevates the hyoid bone.

Innervation - C1 nerve roots that run with the hypoglossal nerve