Muscles of Facial Expression

Question 1

Innervation and action:
frontal belly of occiptofrontalis (frontalis)

Answer 1

innervation: temporal branch of the facial nerve
action: wrinkle the forehead & elevate the eyebrows

Question 2

Innervation and action:
occipital belly of occiptofrontalis

Answer 2

innervation: posterior auricular branch of the facial nerve
action: retract the scalp

Question 3

Innervation and action:
orbicularis occuli

Answer 3

Innervation: temporal and zygomatic branches of the facial nerve

Action - two parts:
orbital part (outer) - forceful closure of eye
palpebral part (inner) - gentle closure of eyes (blinking)

Question 4

Innervation and action:
orbicularis oris

Answer 4

innervation: buccal and marginal mandibular branches of facial nerve

Action: Its actions are to close &/or protrude the lips
Together with the buccinator & tongue, keeps food between occlusal surfaces of teeth

Question 5

Innervation and action:
Buccinator

Answer 5

innervation: buccal branch of facial nerve

action: to press the cheeks against the molar teeth & works with the tongue to keep food between occlusal surfaces of teeth & out of the oral vestibule
- helps with chewing but not a MOM

Question 6

Innervation and action:
Platysma

Answer 6

innervation : cervical branch of the facial nerve

action: to tense the skin of inferior face/neck & depress the mandible

Question 7

dilators which insert into angle of the mouth

Answer 7

-zygomaticus major
-risorius
- levator anguli oris
- depressor anguli oris

Question 8

dilators which insert into upper or lower lips

Answer 8

-zygomaticus minor
-levator labii superioris
-depressor labii inferioris

Question 9

muscles of expression: nose

Answer 9

-levator labii superioris alequae nasi
- nasalis
-depressor septi

Question 10

action of levator labii superioris alequae nasi

Answer 10

flaring of nostrils

Question 11

nasalis - different parts and action

Answer 11

-transverse (middle)
-alar
wrinkles skin over dorsum of nose

Question 12

nerve control of corneal reflex (blink reflex)

Answer 12

afferent fibres: opthalmic division of the trigeminal nerve (CN V) senses the stimulus on the cornea

efferent fibres: facial nerve (CN VII) initiate the motor response in the orbicularis occuli muscle

Question 13

what are all muscles of facial expression derivatives of

Answer 13

2nd pharyngeal arch derivatives