Unit 2 Actions and Innervations

Question 1

stylohyoid

Answer 1

action: depress hyoid during swallowing

innervation: ansa cervicalis

Question 2

omohyoid

Answer 2

action: depress and retract hyoid

innervation: ansa cervicalis

Question 3

sternothyroid

Answer 3

action: depress hyoid and larynx

innervation: ansa cervicalis

Question 4

Thyrohyoid

Answer 4

Action: depress hyoid and larynx

Innervation: C1 via hypoglossal nerve (CNXII)

Question 5

Mylohyoid

Answer 5

Action: elevates hyoid and floor of mouth during swallowing

Innervation: CN V3

Question 6

Geniohyoid

Answer 6

Action: pulls hyoid superiorly

Innervation: C1 ventral ramus via hypoglossal n

Question 7

Stylohyoid

Answer 7

Action: elevates and retracts hyoid

Innervation: CN VII (facial)

Question 8

Digastric

Answer 8

Action: depress mandible; steadies hyoid

Innervation: CNV anterior belly; CN VII posterior belly

Question 9

Obicularis oculi

Answer 9

Action: closes eyelid

Innervation: CN VII

Question 10

Occipitofrontalis

Answer 10

Action: raises eyebrows and wrinkles skin of forehead; protracts scalp (pulls it back)

Innervation: CNVII

Question 11

Corrugator supercilli

Answer 11

Action: draws eyebrows medially down

Innervation: CNVII

Question 12

Procerus

Answer 12

Action: depresses medial eyebrow; makes transverse wrinkle in forehead

Innervation: CNVII

Question 13

Nasalis

Answer 13

action: widens nasal aperture

innervation: CNVII

Question 14

levator labii superioris alaeque nasi (LLSAN)

Answer 14

action: everts upper lip and dilates nostrils

innervation: CNVII

Question 15

levator labii superioris

Answer 15

action: elevates and everts upper lip

innervation: CNVII

Question 16

zygomaticus major and minor

Answer 16

action: elevates upper lip, retracts buccal angle

innervation: CNVII

Question 17

levator anguli oris

Answer 17

action: raise buccal angle

innervation: CNVII

Question 18

buccinator

Answer 18

action: compresses cheeks against teeth, tighten cheeks when expelling air

innervation: CNVII

Question 19

mentalis

Answer 19

action: wrinkles chin skin

innervation: CNVII

Question 20

depressor labii inerioris

Answer 20

action: depresses and everts lower lip

innervation: CNVII

Question 21

depressor anguli oris

Answer 21

action: depresses buccal angle

innervation: CNVII

Question 22

obicularis oris

Answer 22

action: closes, purses, protrudes lips

innervation: CNVII

Question 23

platysma

Answer 23

action: depresses mandible and tenses skin of neck

innervation: CNVII

Question 24

risorius

Answer 24

action: pulls buccal angle laterally

innervation: CNVII

Question 25

levator palpebrae superiorus

Answer 25

action: elevates upper eyelid

innervation: CN III (oculomotor)

Question 26

medial rectus

Answer 26

action: adduction of eyeball

innervation: CN III (oculomotor)

Question 27

lateral rectus

Answer 27

action: abduction of eyeball

innervation: CN VI (abducens)

Question 28

superior rectus

Answer 28

action: elevates, adducts, medially rotates eyeball

innervation: CN III (oculomotor)

Question 29

inferior rectus

Answer 29

action: depress, adducts, laterally rotates eyeball

innervation: CN III (oculomotor)

Question 30

superior oblique

Answer 30

action: depress, abduct, medial rotate eyeball (down and out)

innervation: CNIV (trochlear)

Question 31

inferior oblique

Answer 31

action: elevate, abduct, and medially rotate eyeball (up and out)

innervation: CN III (oculomotor)