Superficial muscles of the face Flashcards
Describe briefly the cutaneous nerve supply of the face and scalp?
Motor innervation of the face is via CN VII
Sensory innervation- angle of the mandible is supplied via great auricular nerve (C2 and C3 via cervical plexus) and rest of the face via CN V
Describe the attachments, nerve supply and action of orbicularis oculi
Palpebral part:
- origin= medial palpebral ligament
- insertion= lateral palpebral raphe at the ligament
Orbital part:
- origin= nasal part of frontal bone, frontal process of maxilla and medial palpebral ligament
- insertion= skin around margin/ orbit
nerve supply- temporal and zygomatic branch CN VII
action- gently close eyelid, involuntary (palpebral), tightly close eyelid, voluntary (orbital)
Describe the attachments, nerve supply and action of orbicularis oris
origin- buccinator/ surrounding muscles and medial mandible/ maxilla
insertion- mucous membrane of lips
nerve supply- mandibular branch CN VII
action- keeps food between occlusal surfaces of teeth
Describe the attachments, nerve supply and action of buccinator
origin- posterior part of alveolar process of maxilla/ mandible and pterygomandibular raphe
insertion- merge with fibres of orbicularis oris
nerve supply- buccal branch CN VII
action- puff cheeks out, smiling, presses cheeks against molars, keeps food within occlusal surfaces and out of oral vestibule
what is a buccal fat pad?
buccal fat pad is much larger in children to reinforce cheeks when feeding- associated with chubby cheeks
lies superficial to buccinator and is pierced by parotid duct
Describe the attachments, nerve supply and action of platysma
origin- subcutaneous tissue of infra and supraclavicular regions
insertion- base of mandible to merge with orbicularis oris
Describe the attachments, nerve supply and action of occipitofrontalis?
frontal belly:
origin- epicranial aponeurosis
insertion- subcutaneous tissue of eyebrows and forehead
occipital belly:
origin- lateral 2/3 of superior nuchal line
insertion- epicranial aponeurosis
nerve supply- frontal= temporal branch, occipital= posterior auricular branch CN VII
action- wrinkle forehead, raise eyebrows, retract scalp
what is the function of superior nuchal line
prevents spread of infection
what is the action of dilator muscles around the mouth?
to widen, lift or depress the corners of the mouth
give examples of dilator muscles of the mouth
levator anguli oris, depressor anguli oris
zygomaticus major
zygomaticus minor
levator labii superioris
depressor labii inferioris
mentalis
Which muscle is responsible for wrinkling nose?
procerus and transverse part of nasalis
which muscle is responsible for flaring nostrils?
nasalis, together with levator labii superioris and alaeque nasi
describe the innervation, arterial supply and venous drainage of muscles of the ears?
innervation- CN VII
arterial supply- ECA via posterior auricular and superficial temporal arteries
venous drainage- EJV
Why do facial wounds tend to bleed a lot?
facial wounds tend to bleed a lot as the terminal branches of ICA and ECA anastomose in the midline (as well as veins)
Where can a pulse be taken in the face?
from transverse facial artery, anterior to auricle
superficial temporal artery where it crosses zygomatic process anterior to auricle
facial pulse can be palpated when someone clenches their teeth- where facial artery crosses inferior border of mandible immediately anterior to masseter muscle
which vein drains most of upper face
Transverse facial vein drains most of the upper face
From which 2 veins is the retromandibular vein formed?
retromandibular vein is formed by the joining of the superficial temporal and maxillary vein
describe the course of retromandibular vein
runs posterior to ramus and emerges from parotid gland inferiorly- dividing into anterior branch (unites with facial vein) and posterior branch (to EJV as it joins with posterior auricular vein)
what is the ‘danger triangle’?
from the corners of mouth to bridge of nose
infection here can travel into cavernous sinus, slow blood flow can cause severe infection - thrombosis spreads intercranially to meninges
why do facial wounds tend to gape open?
facial wounds tend to gape open as the face has no distinct deep fascia- subcutaneous tissue between the cutaneous attachment of facial muscles is loose. blood can accumulate in the face leading to inflammation
What is the innervation of the ears?
All innervated by the CN VII
what is the blood supply of the ears?
ears are supplied by the ECA via posterior auricular and superficial temporal arteries
what structure joins the eyelids together at each angle?
the palpebral fissure
describe the structure of the eyelid?
covered externally by skin, internally by transparent mucous membrane (conjunctiva) which is loosley attached to sclera
-skin
-connective tissue
-conjunctiva
- muscle
- tarsus
- orbital septum
what is the orbital septum?
orbital septum = fibrous membrane from tarsi to margins of orbit when becomes continuous with periosteum of bone - can limit spread of infection from orbit
what is the blood supply of the eyelids?
blood supply of eyelids= ECA via facial, transverse facial, superficial temporal and ICA via supratrochlear, supraorbital and lacrimal
what is the purpose of lacrimal fluid?
lacrimal fluid keeps cornea moist
what is the innervation of the eylids?
innervation of the eyelid comes from CN V1 and V2 (sensory) and motor via temporal and zygomatic branches of CN VII
