infra and supra hyoid muscles

Question 1

suprahyoid

Answer 1

above the hyoid bone

Question 2

infrahyoid

Answer 2

below the hyoid bone

Question 3

suprahyoid muscles

Answer 3

• anterior and posterior belly of digastric
• geniohyoid
  -mylohyoid
  -stylohyoid

Question 4

infrahyoid muscles

Answer 4

• thyrohyoid
  -omohyoid
  -sternohyoid
  -sternothyroid

Question 5

suprahyoid muscles action

Answer 5

raise the hyoid bone as required during swallowing

Question 6

mylohyoid: insertion, innervation

Answer 6

-originates at mylohyoid line of mandible and inserts into body of hyoid (geniohyoid lies on top)
-forms the floor of the oral cavity

innervation: nerve called ‘nerve to mylohyoid’ which is a branch of the inferior alveolar nerve from the mandibular division of the trigeminal nerve

Question 7

anterior belly of digastric: insertion, action and innervation

Answer 7

-anterior belly originates at digastric fossa on lower medial aspect of mandible ; both bellies insert at attachment of their intermediate tendon at hyoid

action: Anterior belly raises hyoid & opens mouth by lowering mandible

innervation: nerve called ‘nerve to mylohyoid’ which is a branch of the inferior alveolar nerve from the mandibular division of the trigeminal nerve
(same as mylohyoid)

Question 8

posterior belly of digastric: insertion, action and innervation

Answer 8

-posterior belly originates at mastoid notch on medial side of mastoid process; both insert at attachment of their intermediate tendon at hyoid

action: posterior belly elevates & retracts hyoid bone

innervation: digastric branch of the facial nerve

Question 9

stylohyoid: insertion and innervation

Answer 9

-originates at the styloid process & inserts into body of hyoid (laterally)

innervation: digastric branch of the facial nerve
(same as posterior belly of digastric)

Question 10

geniohyoid: insertion, innervation

Answer 10

-originates from the mandible (mental spine) & inserts at body of hyoid (located superior to mylohyoid; floor of oral cavity)

innervation: anterior ramus of C1 which travels with the hypoglossal nerve (CN XII)

Question 11

infrahyoid muscles action

Answer 11

depress or fix hyoid bone & provide attachment for suprahyoid muscles

Question 12

sternohyoid innervation

Answer 12

anterior rami of C1-C3 through the ansa cervicalis

Question 13

sternothyroid innervation

Answer 13

anterior rami of C1-C3 through the ansa cervicalis

Question 14

omohyoid innervation

Answer 14

anterior rami of C1-C3 through the ansa cervicalis

Question 15

thyrohyoid innervation

Answer 15

anterior rami of C1 which travel with hypoglossal nerve (CN XII)