Superficial face and muscles of facial expression Flashcards
What is the cutaneous nerve supply of the face? (broad and branches)
TRIGEMINAL NERVE
CNV1 - supraorbital, supratrochlear, infratrochlear, external nasal, lacrimal
CNV2 - zygomaticotemporal, zygomaticofacial, infra-orbital
CNV3 - auriculotemporal, buccal, mental
Also, skin over angle of mandible is the greater auricular nerve (C2 & C3)
What nerve supplies the back of the head?
The greater occipital (from C2)
What nerves supplies the lateral side of neck (over SCM)?
The greater auricular and the lesser occipital (from cervical plexus)
What are the 5 main facial expression muscles?
Orbicularis oculi (palpebral and orbital parts)
Orbicularis oris
Buccinator
Platysma
Occipitofrontalis
Describe the course of the facial nerve
Enters skull - internal acoustic meatus
Gives greater petrosal branch - innervates the lacrimal gland
Before exiting - Nerve to stapedius and chorda tympani.
Exits skull at stylomastoid foramen
Gives digastric branch and posterior auricular nerve (innervates posterior belly of occipitofrontalis and auricular muscles)
Enters partoid to give off 5 terminal branches
What does the temporal branch of CNVII supply?
frontal belly of occipitofrontalis and orbicularis oculi
What does zygomatic branch of CNVII supply?
Orbicularis oculi and upper lip muscles
What does buccal branch of CNVII supply?
Buccinator and orbicularis oris
What does mandibular branch of CNVII supply?
orbicularis oris
What does the cervical branch of CNVII supply?
Platysma
What are the branches of the facial artery?
Superior labial artery
Inferior labial artery
Lateral nasal arteris
Angular artery - terminal branch of facial
What is the intermediate tendon of the occipitofrontalis?
Epicranial aponeurosis
What does the occipitofrontalis muscle do?
Wrinkles the forehead (frontal) and retracts the scalp (occipital)
What is the insertion of the frontal belly of occipitofrontalis and what is the clinical impplication of this?
Skin/ subcutaneous tissue of eyebrows and forehead.
No bony attachment means infection can spread anteriorly into the face through loose connective tissue.
Posterior, superior nuchal attachment prevents spread of infection in the occipital region.
Where does the parotid duct run?
Travels across masseter then pierces buccinator.
What is the orbicularis oculi action?
To close eyelids
What is orbital part of orbicularis aculi action?
close TIGHTLY, VOLUNTARY
What is palpebral part of orbicularis oculi function?
close GENTLY - blinking, INVOLUNTARY blinking reflex
What is unique about external facial veins?
No valves in them - blood flows in both directions.
Profuse bleeding if facial vein is cut/ injured.
Origin and insertion of orbicularis oris?
Origin - buccinator/ surrounding muscles & medial mandible & maxilla
Insertion - mucous membrane of the lips
Action of the orbicularis oris
Clos or protrude the lips
What muscle works with orbicularis oris to keep food between occlusal surfaces of teeth?
Buccinator
Origin and insertion buccinator
Origin - alveolar processes of mandible/ maxilla & pterygomandibular raphe
Insertion - merge with fibres of orbicularis oris
Actions of buccinator
Puff cheeks
Push cheeks against molar teeth, keeps food on occlusal surfaces
Origin and insertion of the platysma
origin - subcutaneous tissue of infra and supraclavicular regions
Insertion - base of mandible to merge with orbicularis oris, skin of cheek, lower lip & angle of mouth
Action of platysma
Tense the skin of inferior face/ neck and depress the mandible
What is generally the venous drainage of the face?
Facial vein drains most of face into IJV.
very variable person to person.
What generally drains the upper part of the face?
Transverse facial vein.
What can result from the venous drainage of the danger triangle of the face and why?
Skin infections can spread from the face into the small caverns of the cavernous sinus where the pathogens multiply.
Infections spread from facial veins and the pterygoid plexus, because there is no deep fascia and subcutaneous tissue is loose - space to travel.
Can lead to cavernous thrombosis or infections spreading intracranially to the meninges.
