Oral and Facial Muscles W2 Flashcards
what is orbicularis oris?
muscle that encircles mouth, fibres of upper and lower lips, horizontal fibres attach to lip and interdigitate to form circle closes mouth, pucker, attachment for other facial muscles, innervated by CN VII facial not a facial muscles, everything orientated to orbicularis oris
what are the transverse facial muscles?
buccinator, risorius
what are the angular facial muscles?
levator labii superior alaeque nas levator labii superiori depressor labii inferiori zygomaticus major zygomaticus minor
what are the vertical facial muscles?
levator anguli oris depressor anguli oris metalus muscle
what is the buccinator?
forms the cheek muscles
deep muscle, deep to risorius and masseter
origin: pterygomandibular ligament and alveolar process of mandible and maxilla
insertion: modiolus and orbicularis oris
maintains food between teeth, allows forced airflow for ‘th’, pulls lips laterally
innervated by CN VII facial
what is the risorius?
overlies buccinator
origin: connective tissue over parotid gland and masseter
insert: modiolus
pulls lips laterally
innervated by CN VII facial
What is zygomaticus major?
lateral to zygomaticus minor
origin: zygomatic bone
insert: modiolus and orbicularis oris
pulls lips laterally and superiorly (amile)
inervated by CN VII facial
what are the primary movers for retraction of the lips?
zygomaticus major, buccinator, risorius
what is zygomaticus minor?
medial to zygomaticus major and lateral to levator labii superioris
origin: zygomatic bone
insrtion: orbicularis oris (upper lip)
pulls upper lip superiorly
innervated by CN VII facial
what is depressor labii inferioris?
origin: inferior mendible (external oblique line)
insertion: orbicularis oris (lower lip)
pulls lower lip inferiorly
innervated by CN VII facial
What is levator labii superioris?
lateral to the levator labii superioris aleque nasi
origin: maxilla (frontal process)
insertion: orbicularis oris (upper lip)
pulls upper lip superiorly
innervated by CN VII facial
what is Levator labii superioris alaeque nasi?
medial to leavtor labii superioris
origin: maxilla forntal process
insert: lateral margin of nose
pulls upper lip superiorly
innervated by cn vii facial
WHat are the primary movers of opening of the lips?
zygomaticus minor, depressor labii inferioris, levator labii superioris, levator labii superioris alaeque nasi
what is the primary mover for closure of the lips?
orbicularis oris
what is levator anguli oris?
lateral to levator labii superioris alaeque nasi
origin: maxilla (canine fossa)
insert: modiolus and orbicularis oris
elevated the angle of the mouth
innervated by cn vii facial
what is depressor anguli oris?
lateral to depressor labii inferioris, continues from levator anguli oris
origin: mandible (oblique line)
insertion: orbicularis oris and modiolus
depresses corners of the mouth
cn vii
what is the platysma?
superficial to most other muscles in this vicinity
covers majority of anterior and lateral neck except depressor anguli oris
variable coverage from tissue around clavicle to modiolus, mouth muscles, cheek, mandible
lowers mandible and skin of lower face
cn vii
what are the primary movers for elevation of the corners of the mouth?
zygomaticus major
levator anguli oris
what are the primary movers for depression of corners of mouth?
platysma, depressor anguli oris
what is the mentalis?
medial to depressor anguli oris and depressor labii inferioris
origin: mandible incisive fossa
insertion: skin of the chin
raises and protrudes lower lip
cn vii
what are the mandible elevator muscles of mastication? (jaw closers)
masseter, temporalis, medial ptyregoid
what is the mandible protrusion muscle of mastication?
lateral ptyregoid muscle
what are the mandible depressor muscles of mastication (jaw openers)
lateral ptyregoid, digastricus, mylohyoid, geniohyoid (ansa cervicalis)
which cranial nerve innervates the muscles of mastication? which muscle is excluded from this?
cn v trigeminal, except for geniohyoid
what is the masseter?
origin: zygomatic arch
insert: external fibres into ramus, internal fibres into coronoid process
elevates mandible
cn v trigeminal
what is the temporalis?
origin: temporal fossa
insert: coronoid process of mandible
elevates the mandible
cn v trigeminal
what is medial ptyregoid?
sit in interior surface of mandible
origin: sphenoid bone (ptyregoid process)
insertion: angle and ramus of the mandible (inside)
elevates mandible
unilateral contraction = lateral jaw movement
cn v trigeminal
what is lateral ptyregoid?
upper and lower head
origin: sphenoid bone
insert: TMJ condyle of the mandible
protrusion and jaw depresson
lateral excursion of the jaw with medial ptyregoids
cn v trigeminal
what is the anterior belly of the digastric?
origin: mandible
insert: intermediate tendon connected to the hyoid bone
opens jaw when hyoid fixed by infrahyoids
raises hyoid up and forwards when mandible fixed
innervated by cn v trigeminal
what is the posterior belly of the digastric?
origin: mastoid notchc of the temporal bone
insert: intermediate tendon connected to hyoid bone
elevayes and retracts hyoid bone when mandible stabilised
innervated by facial nerve cn vii
which belly of digastricus is innervated by facial and which by trigeminal?
anterior trigeminal
posterior facial
what is the mylohyoid?
floor of mouth
origin: mandible (mylohyoid line)
median raphe (other side of mucle) and hyoid bone
jaw depression if hyoid fixed
elevates floor of mouth if jaw fixed
cn v trigeminal
what is geniohyoid?
origin: mandibular symphysis (internal surface)
insert: hyoid bone
2 bellies which sit at midline
elevates hyoid if jaw fixed
jaw opener with other suprahyoid muscles
ansa cervicalis
what are the intrinsic tongue muscles?
superior longitudinal
inferior longitudinal
transverse lingual
vertical lingual
all originate and insert within tongue, all innervated by cnxii hypoglossal
what are thre extrinsic tongue muscles?
palatoglossus (pharyngeal plexus)
styloglossus
hyoglossus
genioglossus
all originate outside the tongue and insert within the tongue, all innervated by vn xii hypoglossal except palatoglossus
what is genioglossus?
extrinsic tongue muscle
origin: mental spine of mandible
strongest and largest tongue muscle
anterior and posterior fibres
posterior fibres: tongue tip protrusion
anterior fibres: tongue retraction
contraction of both: draws middle tongue down
what is palatoglossus?
extrinsic tongue muscle
origin: soft palate
tongue and velar muscle
pharyngeal plexus cn ix x glossopharyngeal and vagus
lowers palate elevates tongue
glossopalatal seal for swallowing
what is styloglossus?
extrinsic tongue muscle
origin: temporal bone (styloid process)
draws tongue back and up
what is hyoglossus?
extrinsic tongue muscle
origin: hyoid
draws tongue down
