Muscles of Facial Expression Flashcards
all muscles of facial expression are supplied by which cranial nerve?
CN7 - Facial
what cranial nerve innervates facial sensation?
trigeminal nerve - CN5
what are the 3 groups of facial muscles?
orbital, nasal, and oral
what are the 2 main muscles of the orbital group? name their sub muscles
orbicularis oculi containing
1. palpebral orbicularis
2. lacrimal orbicularis
3. orbital orbicularis
and corrugator supercilli
function of orbicularis oculi
ctrls movement of eyelids and eyebrows
function of corrugator supercilli
brings brows together (frown)
function of palpebral orbicularis
closes eyelids
function of lacrimal orbicularis
facilitates tear drainage
function of orbital orbicularis
closes eyes tightly
what is myasthenia gravis and which muscle is MOST affected?
chronic autoimmune disease causing muscle weakness. most affected muscle is the orbital orbicularis
what are the muscles of the nasal group?
- nasalis transverse
- nasalis alar
- procerus
- depressor nasi septi
location & function of nasalis transverse
location: arises from maxilla and attaches to aponeurosis across dorsum of nose
function: compresses nostrils
location & function of nasalis alar
location: originates from maxilla
function: flares nostrils
location & function of procerus
location: most superior nasal muscle located between brows
function: pulls skin between brows down and flares nostrils
location & function of depressor nasi septi
relevant surgical procedure
location: arises from maxilla
function: pulls tip of nose down
-sevored during rhinoplasty to correct droopy tip
2 main muscles of oral group
- orbicularis oris
- buccinator
function of orbicularis oris
encloses oral cavity opening
function of buccinator
what condition affects its function
help mastication & blowing
bells palsy
upper group of oral muscles
risorious
zygomaticus major and minor
levator labii superioris
levator labii superioris alaque nasi
levator anguli oris
lower group of oral muscles
depressor anguli oris
depressor labii inferioris
mentalis
location and function epicranius facial muscle (not apart of any category)
location: large muscle covering top of skull
function: raises brows and wrinkles forehead
temporoparietalis location (not apart of any category)
muscle on side of head that does from ear to epicranial aponeurosis
platysma location (not apart of any category)
broad sheet arising from fascia of pectoralis major and deltoid
where does CN7 arise from
pons of brainstem
what can cause loss of function of CN7 and what does it result in
stroke can cause loss of function and results in loss of function of all facial muscles
bells palsy
condition affecting facial nerve
causes twitching, weakness, and loss of movement
usually temporary but can be permanent
what are the muscles of mastication?
- masseter
- temporalis
- medial pterygoid
- lateral pterygoid
masseter description & function
paired, strong and thick muscle that has a deep and superficial part
function: chewing/biting down
temporalis description and function
on each side of head filling temporal fossa and covers most of temporal bone
function: closes and retracts jaw during chewing
medial pterygoid description & function
thick muscle connecting mandible with maxilla, sphenoid, and palatine bones
function: closes jaw & grinds teeth
lateral pterygoid function
opens jaw and grinds food
