muscles of anterior triangle of neck

Question 1

anterior belly of digastric muscle

Answer 1

origin: digastric fossa on mandible
insertion: intermediate tendon
action: raise hyoid bone and depress mandible (when hyoid is fixed)
innerv: mylohyoid nerve (CN 5-3)

Question 2

posterior belly of digastric muscle

Answer 2

origin: mastoid notch
insertion: intermediate tendon
action: raise hyoid bone and depress mandible (when hyoid is fixed)
innerv: facial nerve (CN 7)

Question 3

muscles of the suprahyoid region

Answer 3

stylohyoid, digastric, mylohyoid, geniohyoid

Question 4

muscles of the infrahyoid region

Answer 4

omohyoid, sternohyoid, thyrohyoid, sternothyroid

Question 5

mylohyoid muscle

Answer 5

form the floor of the mouth

origin: mylohyoid ridge on mandible
insert: hyoid bone
action: support/elevates the floor of the mouth and hyoid bone (swallowing), draws hyoid bone forward, helps open mandible
innerv: mylohyoid n (CN 5-3)

Question 6

geniohyoid muscle

Answer 6

origin: inferior mental spine of mandible
insert: hyoid bone
action: raises and pulls forward hyoid bone (swallowing), helps open mandible
innerv: branch of C1

Question 7

stylohyoid muscle

Answer 7

origin: styloid process
insert: hyoid bone
action: raises hyoid bone (swallowing)
* doesnt help with opening mandible
innerv: facial nerve

Question 8

sternohyoid muscle

Answer 8

origin: clavicle and manubrium
insert: hyoid bone
action: depress hyoid bone and larynx
innerv: C1 to C3 (ansa cervicalis)

Question 9

inferior belly of omohyoid muscle

Answer 9

origin: scapula
insert: intermediate tendon
action: lower/fix hyoid bone
innerv: C1 to C3 (ansa cervicalis)

Question 10

superior belly of omohyoid muscle

Answer 10

origin: intermediate tendon (clavicle)
insert: hyoid bone
action: lower/fix hyoid bone
innerv: C1 to C3 (ansa cervicalis)

Question 11

thyrohyoid muscle

Answer 11

found under sternohyoid muscle

origin: oblique line of thyroid cartilage
insert: hyoid bone
action: depress hyoid, if hyoid is fixed: raise larynx
innerv: C1

Question 12

sternothyroid muscle

Answer 12

• not attached to hyoid bone
  origin: manubrium
  insert: oblique line of thyroid cartilage
  action: moves larynx down
  innerv: C1 to C3 (ansa cervicalis)

Question 13

what muscles do mylohyoid nerve innervate?

Answer 13

1) anterior belly of digastric muscle

2) mylohyoid muscle

Question 14

what muscles do facial nerve innervate?

Answer 14

1) posterior belly of digastric muscle

2) stylohyoid muscle

Question 15

what muscles do C1 innervate?

Answer 15

1) geniohyoid muscle

2) thyrohyoid muscle

Question 16

what muscles do ansa cervicalis (C1 to C3) innervate?

Answer 16

1) sternohyoid muscle
2) inferior belly of omohyoid muscle
3) superior belly of omohyoid muscle
4) sternothyroid muscle