Lecture 9 - Face & Muscles of Facial Expression Flashcards
What are the 3 groups of muscles of facial expression?
orbital, nasal and oral
What are the muscles of the orbital group?
occipitofrontalis and orbicularis oculi
What is the origin and insertion of the occipitofrontalis muscle?
spans between skin / subcutaneous tissue of forehead & superior nuchal line with epicranial aponeurosis in the middle
What is the function of the occipitofrontalis?
elevates eyebrows, wrinkles forehead, & pulls scalp posteriorly
What is the origin and insertion of the orbicularis oculi?
spans between medial orbital margin / lacrimal bone &
skin around margin of orbit
What is the function of the orbicularis oculi?
voluntary closure of eyelid; squinting / forceful closure of the eye
What are the 5 muscles of the orbital and nasal groups?
- depressor supercilii
- corrugator supercilii
- procerus
- nasalis
- levator labii superioris alaquae nasi
What is the function of the depressor supercilii?
depresses eyebrows
What is the function of the corrugator supercilii?
pulls eyebrows medially and inferiorly
What is the function of the procerus?
pulls eyebrows medially and inferiorly
What is the function of the nasalis?
depresses and/or flares nostrils; wrinkles nose
What is the function of the levator labii superioris alaquae nasi?
flares nostrils and elevates upper lip + side of nose
What are the 5 muscles of the first part of the oral group?
- orbicularis oris
- levator labii superioris
- levator anguli oris
- zygomaticus major
- zygomaticus minor
What is the function of the orbicularis oris?
compresses and protrudes the lips; resists distension when blowing
What is the function of the levator labii superioris?
elevates upper lip
What is the function of the levator anguli oris?
elevates the corners of the mouth; assists with smiling
What is the function of the zygomaticus major?
pulls the corner of the mouth superiorly and laterally (smiling)
What is the function of the zygomaticus minor?
pulls the upper lip superiorly and laterally
What are the 3 muscles of the second part of the oral group?
- depressor angli oris
- depressor labii inferioris
- mentalis
What is the function of the depressor angli oris?
depresses the corner of the mouth
What is the function of the depressor labii inferioris?
depresses the lower lip
What is the function of the mentalis?
elevates and protrudes the lower lip -> pouting
What are the 3 muscles of the third part of the oral group called?
- risorius
- platysma
- buccinator
What is the function of the risorius?
retracts the corner of the mouth -> fake / forced smile”
What is the function of the platysma?
depresses skin of lower face & mouth; tenses skin of neck; aids forced depression of mandible
What is the function of the buccinator?
presses cheek against molars; suckling (nursing infant); resists distension of cheeks; draws mouth to one side
Which duct pierces the buccinator?
the parotid duct
What is the modiolus?
an anatomical landmark at the corner of the mouth where several of muscles
of facial expression converge / intersect
Which 6 muscles meet at the modiolus?
- zyg. maj
- buccinator
- risorius
- obicularis oris
- lev. anguli oris
- dep. anguli oris
What does the modiolus allow?
for integration / coordination of multiple
facial muscles at once
What happens to the modiolus as we age?
begins to droop
& sink
What are all muscles of facial expression innervated by?
facial nerve (and its 5 branches)
What does Bell’s Palsy lead to?
weakness or paralysis in muscles of facial expression on ipsilateral side
Where does injury happen in Bell’s Palsy?
facial nerve or motor branches
What nerve does Ramsay Hunt Syndrome affect?
CN VII
What virus can later reactivate in Ramsay Hunt Syndrome?
shingles or chicken pox
What is sensory innervation of the face carried by?
the 3 divisions of the trigeminal nerve (opthalmic, maxillary, mandibular)
Which level does the bifurcation of the common carotid artery happen?
C4
What are the names of the 8 arteries that supply the head?
- superior thyroid artery
- ascending pharyngeal artery
- lingual artery
- facial artery
- occipital artery
- posterior auricular artery
- maxillary artery
- superficial temporal artery
What two arteries give blood to the face?
facial artery and lingual artery
What are the 8 arteries of the face?
- supraorbital artery
- infraorbital artery
- transverse facial artery
- ophthalmic artery
- facial artery
- maxillary artery
- superficial temporal artery
- external carotid artery
What are the 3 arterial anastomoses of the face?
- supraorbital artery and angular artery
- infraorbital artery and angular artery
- transverse facial artery and angular artery
What does the superficial venous drainage of the face pattern match?
the arterial supply patterns
What is the cavernous sinus?
‘gateway’ for infection to spread into other veins in cranial cavity
Where do the opthalmic veins drain into?
cavernous sinus
What is the facial vein a continuation of?
the angular vein
Where does the facial vein drain into?
internal jugular vein
What are the facial veins closely linked to?
the cavernous sinus
What does the cavernous sinus spread?
infected blood clots and other infections
What is the danger triangle of the face?
bridge of nose to corners of mouth
