Lecture 4.2 - The Face

Question 1

Where do facial muscles attach? What happens when facial muscles contract? Which nerve innervates facial muscles?

Answer 1

• attachments are between the skull and overlying skin
• when a muscles contracts, the skin moves (rather than a joint)
• all innervated by facial nerve (CN VII)

Question 2

What are the parasympathetic function/innervation for the facial nerve?

Answer 2

• lacrimal gland (tears)
• mucous glands of nasal cavity, pharynx, and palate
• submandibular/sublingual salivary gland

Question 3

What are the Special sensory functions of the facial nerve?

Answer 3

taste receptors on anterior 2/3 of tongue

Question 4

What are the somatic motor function/innervations for the facial nerve?

Answer 4

• muscles of facial expression
• stylohyoid m.
• posterior digastric m.

Question 5

Where does the facial nerve cranially exit?

Answer 5

• through the internal acoustic meatus (temporal bone)

- out of the stylomastoid foramen (temporal bone)

Question 6

What are the branches of the facial nerve?

Answer 6

temporal
posterior articular
zygomatic
buccal
mandibular
cervical

Question 7

Function of Occipitofrontalis?

Answer 7

• elevates eyebrows and skin of forehead

- as in a surprised or doubtful look

Question 8

Function of Procerus?

Answer 8

• depresses skin between eyebrows

- as in a look of anger

Question 9

Function of Orbicularis Oculi

Answer 9

• closes eyelids
• • palpebral: gentle
• • orbital: tight

Question 10

Function of Orbicularis Oris?

Answer 10

• compresses and protrudes the lips

- as in puckering/tightly closing lips (duck lips)

Question 11

Function of Buccinator?

Answer 11

• presses cheek agains the molar teeth

- keeps cheek taut when blowing

Question 12

Function of zygomaticus major?

Answer 12

• pulls superiorly on upper lip

- as in smiling

Question 13

Function of Risorius?

Answer 13

• pulls corners of mouth posteriorly

- as in a insincere smile

Question 14

Function of Levator Labii Superioris?

Answer 14

• elevates lips, dilates nostrils, and raises angle of the mouth
• as in Elvis, sneering

Question 15

Function of Depressor Labii Inferioris?

Answer 15

• pulls lower lip inferiorly (to show lower teeth)

Question 16

Function of Depressor anguli oris?

Answer 16

• pulls corners of mouth inferiorly

- as in a frown

Question 17

Function of Mentails?

Answer 17

• elevates and protrudes lower lip

- as in a pout

Question 18

Function of Platysma?

Answer 18

• tenses skin of lower face and neck, depresses mandible

- as in a grimace

Question 19

What is Bell’s Palsy? Symptoms?

Answer 19

• compression of facial nerve due to swelling
• cause unknown; perhaps viral infection
• most recover within 2-8 weeks; some may take 1-2 years to recover
  Symptoms
• inability to raise eyebrow or generate wrinkles on the forehead
• difficulty closing the eye and inability to raise the corner of mouth
• drooping at the corner of mouth and inability to completely close the eye

Question 20

What is the parotid gland and duct? What is its innervation?

Answer 20

• largest salivary gland
• parotid duct crosses surface of masseter then pierces through buccinator to drain saliva into mouth near 2nd upper molar
• facial nerve is embedded within gland, but does not innervate it.
• innervated by glossopharyngeal nerve (CN IX)