Face And Scalp Flashcards
What are the groups of the muscles of the face?
‣ FOUR GROUPS
- orbital group
- nasal group
- oral group
- other
What are the actions of the facial muscles?
‣ ACTION
- muscles of facial expression
- sphincters around eyes and mouth
What are the innervation of facial muscles?
Facial nerves (VII)
What do facial muscles develop from?
2nd pharyngeal arch
What are the orbital group of the facial Muscles?
Orbicularis oculi
‣ completely surrounds each orbit
‣ orbital part
‣ encircles the orbital opening and beyond the rim
‣ closes the eye forcefully
‣ palpebral part
‣ located in the eyelids from the medial corner of eye across each lid to attach laterally
‣ closes the eye gently
Corrugator supercilii
‣ deep to the eyebrows
‣ draws the eyebrow down and medial, and wrinkles the skin above the nose during frowning
What are the nasal facial group muscles?
Nasalis
‣ transverse part - compresses the nares
‣ alar part - draws the alar cartilages down
and lateral, and opens the nares
Procerus ‣ arises from the nasal bone ‣ inserts into the skin of the forehead, between the eyebrows ‣ draws the medial border downward, wrinkling the skin superficial to the nasal bone ‣ active during frowning
Depressor septi nasi
‣ arises from maxilla and inserts into nasal septum
‣ widens the nares by pulling the nose inferiorly
What are the lower group of facial group?
Depressor anguli oris - depresses corner of mouth (frowning)
Depressor labii inferioris - depresses lower lip laterally
Mentalis - positions lip when drinking from a cup, or pouting
What are the upper part of the oral facial group?
Risorius - grin
Zygomaticus major/minor - smile
Levator labii superioris - deepens furrow between nose and mouth
Levator labii superioris alaeque nasi - flaring the nostrils Levator anguli oris - elevates corner of mouth
What does the orbicularis oris do?
Orbicularis oris - narrows the mouth and closes the lips (whistle)
Whaat are the location, attachments, and actions of buccinator?
Buccinator
‣ location
‣ muscular component of the cheek
‣ occupies space between mandible and maxilla deep to other muscles of the face
‣ Attachments ‣ posterior maxilla & mandible opposite molar teeth ‣ pterygomandibular raphe ‣ blends in with fibers of the orbicularis oris ‣ upper fibers enter the lower lip ‣ lower fibers enter the upper lip
‣ Actions
‣ presses cheeks against teeth (aids in mastication)
‣ forceful expulsion of air from cheeks
What facial muscles fall within the other category?
Other muscles - not in area of face, but derived from 2nd pharyngeal arch and innervated by facial nerve (CNVII)
Platysma
‣ imbedded in superficial cervical fascia
Auricular muscles
‣ anterior auricular
‣ superior auricular
‣ posterior auricular
Posterior belly of digastric
Stylohyoid
Occipitofrontalis
‣ frontal belly
‣ occipital belly
Explain the Anatomy of the occipitofrontalis
ccipitofrontalis
‣ Occipitalis
‣ innervated by posterior auricular branch (CN VII)
‣ attached to superior nuchal line and mastoid process of the temporal bone to epicranial aponeurosis
‣ Frontalis
‣ innervated by temporal branch (CN VII)
‣ attached to skin of eyebrows to epicranial aponeurosis
What is the action of the occipitofrontalis?
‣ moves the scalp, wrinkles the forehead, and raises the eyebrows
What is the occipitofrontalis separated by?
Separated by an aponeurosis
‣ epicranial aponeurosis (galea aponeurotica) – embedded in scalp
Explain the motor innervation to thee face
- motor portion of the facial nerve (CN VII) exits the skull via the stylomastoid foramen (*innervates stapedius muscle inside skull)
- gives the following extracranial branches before coursing anteriorly and entering the substance of the parotid gland:
- posterior auricular n. – to auricularis posterior m. and occipitalis m.
- branch to posterior belly of digastric m. and stylohyoid m.
• The rest of CNVII innervates the muscles of facial expression (5 branches)
What are the CN VII branches?
CN VII enters the parotid gland and divides into 5 motor branches:
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
“Two Zebras Bit My Clavicle”
What is the parotid gland?
‣ anterior to lower half of ear and extends from zygomatic arch down to lower border of mandible
‣ covers portion of SCM and masseter m.
What structures pass through the parotid gland?
Structures passing through the gland:
- Facial n. (CN VII)
‣ after exiting skull (through stylomastoid foramen), enters parotid gland and gives rise to five motor branches
‣ pathology/trauma of parotid gland may result in facial palsy - ECA and its branches
‣ posterior auricular, transverse facial, maxillary, superficial temporal a. - Retromandibular vein
‣ superficial temporal vein + maxillary vein
What is the blood supply & innervation of the parotid gland?
Blood supply & innervation ‣ via numerous arteries that pass through the gland (sup. temporal, post. auricular) ‣ sensory: auriculotemporal nerve (V3) ‣ secretomotor: CN IX > otic ganglion > CN V3
Describe the parotid duct
Parotid duct
Pathway to oral cavity:
‣ leaves anterior edge of gland midway between zygomatic arch and corner of mouth
‣ crosses the anteromedial limit of masseter, penetrates the buccal fat pad and buccinator.
‣ opens opposite 2nd upper molar tooth.
What are the sensory branches from V1?
V1 supraorbital supratrochlear infratrochlear external nasal lacrimal
What are the sensory branches of V2?
V2
zygomaticotemporal
zygomaticofacial
infraorbital
What are the sensory branches of V3?
V3
auriculotemporal
buccal
mental
The terminal branches of CN V provide…
Cutaneous innervation to the face and scalp regions
What is the sensory distribution of CN V1?
ophthalmic nerve (CN V1) 1. supratrochlear & supraorbital -upper eyelid, forehead, scalp
- infratrochlear - medial half of upper eyelid, medial angle, side of nose
- external nasal - anterior nose
- lacrimal - lateral half of upper eyelid, skin
of lateral angle
What is the sensory distribution of CN V2?
Maxillary nerve(CN V2)
- zygomaticotemporal - anterior temple above the zygomatic arch
- zygomaticofacial - small area over zygomatic bone
- infra-orbital - lower eyelid, cheek, side of nose, upper lip
What is the sensory distribution of CN V3?
Mandibular nerve (CN V3)
- auriculotemporal – over the temple
- buccal – cheek area
- mental – over the chin
What are the branches of the external carotid artery?
External carotid artery
‣ Facial artery
‣ angular artery
‣ superior labial branch
‣ inferior labial branch
‣ Superficial temporal artery
‣ transverse facial artery
‣ Maxillary artery
‣ infra-orbital
‣ buccal
‣ mental
What are the internal carotid artery?
Internal carotid artery
‣ Ophthalmic artery
‣ supratrochlear
‣ supraorbital
‣ dorsal nasalWhat are the veins that drain the face?
‣ Facial vein ‣ supratrochlear ‣ supraorbital ‣ angular ‣ Transverse facial vein
What are the intracranial venous connections?
Emissary veins
‣ connect extracranial veins with intracranial veins
Facial vein communicates with deeper veins: ‣ ophthalmic veins ‣ infra-orbital vein ‣ pterygoid plexus of veins ‣ cavernous sinus
All provide a possible route of entry for infections from face and scalp to deep intracranial venous structures
Describe the lymphatic drainage of the face
Submental nodes
‣ drain lymphatics from medial part of lower lip and chin
Submandibular nodes
‣ drain medial corner of the orbit, external nose, medial cheek, upper lip, and lateral part of lower lip
Pre-auricular and parotid nodes
‣ drain lymphatics from eyelids, external nose, and lateral cheek
What are the layers of the scalp in order?
Skin Connective tissue (dense) Aponeurotic layer Loose connective tissue Pericranium
Describe the scalp proper of the skull
Scalp Proper
‣ first three layers are intimately attached
‣ Skin – contains hair follicles
‣ Connective tissue (dense) - connects skin to aponeurotic layer
‣ Aponeurotic layer - contains occipitofrontalis m.
Describe the loose connective tissue proper of the scalp
Loose connective tissue
‣ facilitates movement of the scalp proper over the calvaria (facilitates scalp removal)
‣ ‘Danger zone’ - infections can easily spread through this layer to emissary vein and cranium
Describe the pericranium of the skull
‣ the periosteum on the outer calvaria fuses at the
Emissary v.
suture lines
What are extracranial swellings?
- type, based on where the swelling is located
- due to fluid accumulation or ruptured vessels (as
may be seen during vaginal deliveries) - usually non-life threatening and resolve with time
(no pressure on brain)
What are the types of extracranial swellings?
- Caput succedaneum
- soft superficial swelling just under the skin
- visible from time of birth
- Subgaleal hemorrhage
- hemorrhage between the aponeurotic layer
and periosteum - develops few hours after delivery
- can involve large amount of blood
- hemorrhage between the aponeurotic layer
Cephalohematoma
- hemorrhage between the periosteum and bone
- usually appears within 24-72hrs after delivery and may take weeks to resolve
- does not cross suture lines since periosteum fuses (confined to individual bones)
Describe the innervation of the anterior scalp
Anterior to the ears and the vertex – Trigeminal nerve (CNV) ‣ supratrochlear (CN V1) ‣ supraorbital (CN V1) ‣ zygomaticotemporal (CN V2) ‣ auriculotemporal (CN V3)
Describe the innervation of the posterior scalp
Posterior to the ears and the vertex - branches from spinal nerves (C2/C3) ‣ great auricular ‣ lesser occipital ‣ greater occipital ‣ third occipital
What are the arteries of the scalp?
Arteries ‣ Branches of ECA ‣ superficial temporal a. ‣ posterior auricular a. ‣ occipital a.
‣ Ophthalmic a. (branch of ICA)
‣ supratrochlear a.
‣ supraorbital a.
What are the veins of the scalp?
Veins
‣ supratrochlear v.
‣ supraorbital v.
‣ superficial temporal v.
‣ drains lateral area of scalp and forms retromandibular v.
‣ posterior auricular v.
‣ occipital v.Describe the lymphatic drainage of the scalp
- Generally follows arterial distribution
Occipital region
‣ occipital nodes
‣ upper deep cervical nodes
Upper part of the scalp
‣ posterior to the vertex
‣ mastoid nodes
‣ upper deep cervical nodes
‣ anterior to the vertex
‣ pre-auricular
‣ parotid nodes
‣ forehead
‣ submandibular nodes following facial a.
What are the consequences of CN VII lesion?
UMN (upper motor neuron) lesion of CN VII: sparing of ‘forehead’ muscles’
LMN (lower motor neuron) lesion of CN VII: entire half side of face is paralyzed
Bell’s palsy is a LMN lesion of CN VII which is temporary and should not be able to be traced to a cause other than a possible viral infection
LMN lesion of CN VII: Orbicularis oris muscle not working; drooling, can’t whistle. Orbicularis oculi not working; tearing (lesstearing when GPN is also affected), cannot close eye, reflexes that have CN VII as efferent reflex arc are affected.
Operations in neck where platysma is located: when closing the skin pay attention to the platysma; needs to be approximated to avoid a gap/dimple post surgery.
Degloving operation for removal of meningioma, access to pituitary gland, and other brain surgery. Coronal incision in the hairline, SCAL pulled forwards, opening into the skull is made for access.
