Anterior Muscles of the Neck- Suprahyoid and Infrahyoid

Question 1

Anterior belly of the digastric muscle innervation

Answer 1

mylohyoid branch of the inferior alveolar n. (mandibular branch of the trigeminal nerve–> CN V(3))

-branches of the trigeminal nerve include: 1. ophthalmic, 2. maxillary, 3. mandibular

Question 2

Anterior belly of the digastric muscle attachments

Answer 2

digastric fossa of the mandible–> intermediate tendon

greater cornu of hyoid) (inf. border of the mandible near symphysis to int. tendon and body and cornu of hyoid

Question 3

Anterior belly of the digastric muscle actions

Answer 3

depression of mandible bone, elevation of hyoid bone

Question 4

Posterior belly of the digastric muscle innervation

Answer 4

facial nerve (CN VII)

Question 5

Posterior belly of the digastric muscle attachments

Answer 5

inferior genial tubercle of the mandible–> anterior aspect of the body of the hyoid bone

(median ridge of mandible to body of hyoid)

Question 6

Posterior belly of the digastric muscle function

Answer 6

depression of the mandible or elevation of the hyoid

Question 7

Name the 4 suprahyoid muscles of the anterior neck

Answer 7

1. digastric
   
   • anterior belly
   • posterior belly
2. mylohyoid
3. geniohyoid
4. stylohyoid

Question 8

Mylohyoid muscle innervation

Answer 8

mylohyoid branch of the inferior alveolar n. (from CN V(3) - mandibular branch of the trigeminal nerve)

—> * anterior belly of the digastric muscle is also innervated by the same nerve - two muscles are located adjacent to one another

–> mylohyoid muscle is directly deep to the anterior belly of the digastric muscle

Question 9

Mylohyoid muscle attachments

Answer 9

mylohyoid line of the mandible —> midline raphe and anterior aspect of the body of the hyoid

Question 10

Mylohyoid muscle actions

Answer 10

elevation of the floor of the oral cavity

Question 11

Geniohyoid muscle innervation

Answer 11

ventral ramus of C1 spinal nerve via CN XII

(via hypoglossal nerve)

• same innervation as thyrohyoid muscle (an infrahyoid muscle)

Question 12

Geniohyoid attachments

Answer 12

(deep to the other neck muscles)

inferior genial tubercle of the mandible—> anterior aspect of the body of the hyoid (median ridge of mandible to body of hyoid)

Question 13

Function of the geniohyoid

Answer 13

elevation of tongue, elevation of hyoid, depression of mandible

Question 14

Stylohyoid innervation

Answer 14

facial nerve - CN VII

** posterior belly of the digastric muscle is also innervated by the facial nerve

Question 15

Stylohyoid attachments

Answer 15

styloid process of the temporal bone —> body of the hyoid bone

Question 16

Stylohyoid innervation

Answer 16

facial nerve CN VII

Question 17

Name the 4 infrahyoid muscles that are present in the anterior neck:

Answer 17

1. omohyoid
   
   • superior belly
   • inferior belly
2. sternohyoid
3. sternothyroid
4. thyrohyoid

Question 18

Superior belly of the omohyoid muscle- innervation

Answer 18

ansa cervicalis (C1-3)

Question 19

inferior belly of the omohyoid muscle- attachments

Answer 19

superior border of the scapula medial to the scapular notch –> lateral aspect of the hyoid through an intermediate tendon sling that is loosely associated with the clavicle and 1st rib

Question 20

Superior belly of the omohyoid muscle- function

Answer 20

depression of the hyoid bone

Question 21

Inferior belly of the omohyoid muscle- innervation

Answer 21

ansa cervicalis (C1-3)

Question 22

Inferior belly of the omohyoid muscle - attachments

Answer 22

superior border of the scapula medial to the scapular notch –> lateral aspect of the hyoid through an intermediate tendon sling that is loosely associated with the clavicle and 1st rib

Question 23

Inferior belly of the omohyoid- function

Answer 23

depression of the hyoid bone

Question 24

Sternohyoid muscle- innervation

Answer 24

ansa cervicalis (C1-3)

Question 25

Sternohyoid muscle- attachments

Answer 25

posterior side of the proximal clavicle & adjacent manubrium –> the inferior border of body of the hyoid

Question 26

sternohyoid muscle- actions

Answer 26

depresses the hyoid

Question 27

Sternothyroid- innervation

Answer 27

ansa cervicalis (C1-3)

Question 28

Sternothyroid- attachments

Answer 28

from the posterior aspect of the manubrium & costal cartilage of 1st rib –> the thyroid lamina

Question 29

Sternothyroid- function

Answer 29

depression of an elevated larynx

Question 30

Thyrohyoid innervation

Answer 30

C1 spinal nerve via CN XII - hypoglossal nerve

Question 31

Thryohyoid attachments

Answer 31

from the thyroid lamina to the greater horn of the hyoid bone

Question 32

Thyrohyoid function

Answer 32

depression of hyoid

elevation of the thyroid cartilage