Muscles of Facial Expression Flashcards
Where are the muscles of facial expression found (with regards to fascia)
Muscles of facial expression are found in the superficial fascia around facial orifices
Where do muscles of facial expression tend to originate?
Bone or fascia
Where do muscles of facial expression tend to insert?
Skin
Where do wrinkles form?
Wrinkles form at 90 degrees to the muscle fibre direction
What cranial nerve innervates the muscles of facial expression?
CN VII (facial nerve)
What are the 2 functions of muscle of facial expression
Dilators and Sphincters -
control the opening of facial orifices
Movers of overlying skin -
reflect various facial expressions
How are the muscles of facial expression grouped?
By regions
What are the 5 muscles of facial expression of the mouth?
1- Obicularis Oris 2-Levator Anguli Oris 3- Depressor Anguli Oris 4- Zygomaticus Major 5- Risorius
Obicularis Oris? (OPENS)
Sphincter encircling mouth.
Fibres originate mainly from contributions of other facial muscles, also from labial alveolar bone
Closes oral aperture, protrude lips, press lips against teeth
Levator Anguli Oris? (SMILE)
Originates at the canine fossa
Inserts at the angle of the mouth, blends with fibres of Obicularis Oris
Acts to lift the angle of the mouth
Depressor Anguli Oris? (SAD)
Triangular muscle
Base: originates from external oblique line of mandible
Apex: fibres ascend and converge to apex at angle of mouth, blend with fibres of obicularis oris
Acts to pull angle of mouth downwards
Zygomaticus Major (LAUGHING)
Arises: facial aspect of zygomatic bone
Inserts: fibres descend down and medially to the angle of the mouth, blend with fibres of obicularis oris
Acts to lift angle of mouth upward and backward
Risorius (GRINNING)
Thin, wispy but large
Arises: parotid fascia, small contribution from platysma fibres
Inserts: transversely into angle of mouth
Acts to retract angle of the mouth backwards
What are the 3 muscles of facial expression associated with the lips of the mouth?
Quadratus Superioris
Depressor Labii Inferioris
Depressor Anguli Oris
What 4 muscles compose the quadratus superioris?
1-Zygomaticus Major (as above)
2-Zygomaticus Minor - just medial to z major, lifts angle of mouth
3-Levator Labii Superioris -, medial to z minor, lifts UPPER lip
[[levator anguli oris - medial to LLS, lifts corner of mouth]]
4- Levator Labii Superioris Alaeque Nasi - lifts upper lip and alar cartilage of nose
Depressor Labii Inferioris?
Arises: lower portion of oblique line of mandible
Inserts: lower lip
Acts: depresses LOWER lip
Depressor Anguli Oris?
Most superficial of all lower oral muscles
Arises: chin
Inserts: modiolus (corner of mouth)
Acts: depresses angle of mouth
What is the muscle of facial expression which extends from the front of the head to the back of the head?
The occipitofrontalis: Starts at Occipital belly: arises - from superior nuchal line and mastoid process inserts - epicranial aponeurosis Ends with Frontal belly: arises - epicranial aponeurosis inserts - obicularis oculi
What is the acronym for SCALP?
Skin Connective tissue (highly vascularised) Aponeurosis Loose connective tissue Pericranium
What is the muscle of facial expression associated with the cheek?
Buccinator
Buccinator?
Origin: pterygomandibular raphé, alveolar processes of maxilla and mandible
Fibres sweep forward through cheek as flattened sheet
Insertion: Inferior fibres sweep upwards and superior fibres sweep downwards to blend with obicularis oris
Action:
Prevents cheeks from expanding when forcefully pushing out air (brass instruments)
AIDS in mastication (but still classed muscle of facial expression) as pushes cheeks against vestibular surfaces of molar teeth and so pushes food onto occlusal surfaces of teeth.
What is the muscle of facial expression associated with the chin?
Mentalis
Mentalis?
deep to depressor labii inferioris and depressor anguli oris.
Conical muscle
Origin: incisive fossa
Insertion: skin of chin
Acts: contraction puckers skin overlying chin which help obicularis oris to clear food from mandibular labial vestibule
What is the muscle of facial expression associated with the eye?
Obicularis Oculi
Briefly describe Obicularis Oculi
Sphincter muscle which opens/closes eye
What are the 3 components of the obicularis oculi?
Orbital portion
Palpebral portion
Lacrimal portion
What is the origin, insertion and action of the orbital portion?
Origin: bone of upper medial orbital margin
Insertion: from below at prominent medial palpebral ligament (ligament into anterior lacrimal crest of maxilla)
Action: FORCIBLY squeeze eyes shut
What is the origin, insertion and action of the palpebral portion?
Origin: medial palpebral ligament
Fibres sweep across upper and lower eyelids individually from medial palpebral ligament to interdigitate at the lateral palpebral ligament
Action: lightly approximates eyelids (light blinking/sleeping)
What is the origin, insertion and action of the lacrimal portion?
(small)
Origin: lacrimal bone deep behind lacrimal sac
Insertion: medial portions of lids
Action: holds lids against eyeballfor more even distribution of moistening tears and guides tears to tear duct
What is the muscle associated with the nose?
Nasalis
What are the 2 portions of the nasalis?
transverse portion and alar portion
What is the origin, insertion and action of the transverse portion of the nasalis?
Origin: upper portion of the canine ridge of the maxilla
Insertion: midline aponeurosis (then into bilateral counterpart)
Action: flare nostrils
What is the origin, insertion and action of the alar portion of the nasalis?
Origin: nasal margin of maxilla
Insertion: skin of nostrils
Action: flare nostrils
What are the branches of the facial nerve?
Posterior Auricular Temporal Zygomatic Buccal Mandibular Cervical
Where does the facial nerve divide?
Within the parotid gland
Where does the facial nerve exit the skull?
into internal acoustic meatus, through facial canal and out through stylomastoid foramen.
What causes Bell’s Palsy and what is the recovery like?
Bell’s Palsy is a viral infection of the facial nerve. there is good recovery after a course of corticosteroids
What are the clinical tests for motor function of the facial nerve?
ask patient:
- frown
- close eyes TIGHTLY
- smile
- puff out cheeks
Where does the facial artery arise from?
The external carotid
Which facial veins drain to the external jugular?
Facial vein, common facial vein
What is the pterygoid venous plexus?
collection of veins forming a plexus of considerable size which sits between the temporalis muscle and lateral pterygoid
What does the pterygoid venous plexus communicate with and what does this mean clinically?
namely with:
the deep facial vein, incl. alveolar, palatine, buccal veins etc.
and
the cavernous sinus, which surrounds the pituitary gland
This means that infection of the superficial face may travel to the cavernous sinus and cause cavernous sinus thrombosis.
What are the symptoms of cavernous sinus thrombosis?
Edema of eyelids,
Conjunctivitis,
Paralysis of cranial nerves
What is the general path of the facial artery?
anterior to the anterior aspect of the massester, and then of buccinator, crosses angle of mouth
What is the general path of the facial vein?
Runs anterior to the anterior aspect of the massester. Superior to the facial artery. Crosses at the corner of the nose.
What do superficial lymphatics follow?
VEINS
What do deep lymphatics follow?
ARTERIES
If facial controls MOTOR of face, what controls SENSORY to face??
Greater Auricular Nerve (C2, C3)
Cranial Nerve V (Trigeminal)
Where does the greater auricular nerve innervate?
The angle of the mandible and lower part of ear lobe
Where is the dermatome for the ophthalmic branch of V? (V1)
orbit, mid-nose, forehead
Where is the dermatome for the maxillary branch of V? (V2)
maxilla, anterior temple
Where is the dermatome for the mandibular branch of V? (V3)
mandible, mid-temple, anterior ear
What are the branches of the ophthalmic division?
SUPRAORBITAL, lacrimal, supra-trochlear, infra-trochlear, external nasal
What are the branches of the maxillary division?
INFRAORBITAL, zygomatico-facial, zygomaticotemporal
What are the branches of the mandibular division?
MENTAL, long buccal, auriculo-temporal
Where do the mental nerves, infra-orbital nerves, zygomatico-facial nerves and supra-orbital nerves exit the viscerocranium?
Through their respective foramina of the same name
Where do the the supra-orbital, infra-orbital and mental nerves divide?
The trigeminal sensory ganglion
What are the clinical testsfor sensory innervation to the face?
Ask patient to close their eyes
Gently brush the skin in each dermatome with a fine tip of cotton wool
Ask the patient to tell you when they feel their skin is being touched
Compare the 2 sides