Superficial Face Anatomy Flashcards
What is meant by the neurocranium?
What bones make up the neurocranium?
Bones protecting the brain
Frontal, sphenoid, temporal, parietal, occipital, ethmoid bone
What is meant by the viscerocranium?
What bones make it up?
Makes up the structure of/protects the face - think gives shape to the face.
Zygomatic x2
Lacrimal x2
Nasal x2
Inferior nasal conchae x2
Palatine x2
Vomer
Mandible
Maxilla
Name the bones found in the orbit?
a - sphenoid
B - frontal
C - ethmoid bone
D - maxilla
E - lacrimal
F - zygomatic
Name the bone
Zygomatic bone
Name the bone
Located in the floor of the nasal cavity between the sphenoid and the maxilla, makes up 1/3 of the hard palate found in the roof of the oral cavity.
The palatine bone
What are the different layers of the scalp?
Skin
Connective tissue (dense)
Aponeurosis
Loose areolar layer (danger layer)
Pericranium
What is meant by the calvaria?
What bones make it up?
The roof of the cranial cavity
The temporal, pariteal, frontal, sphenoid and occipital.
What is the yellow label on this image?
Sphenoid bone
What is the orange bone?
Zygomatic bone
What is the first label?
Feature of the frontal bone
Supraorbital notches
What are the features found on the mandible?
Alveolar processes
Mental foramen
What is the feature on the maxilla?
Infraorbital foramen
What is the pterion?
Why is it clinically important?
Found on the lateral view of the skull
Made of the H shaped unification of the parietal, sqaoumous temporal, frontal and sphenoid bones.
Weakest part of the skull
Overlies the middle meningeal artery - risk of epidural hematoma.
What type of hematoma is shown on this MRI?
Epidural
Pear shaped
Concave into the brain
Dural remains fixed onto the brain.
Subdural is more crescent shaped -spread around then down.
What are the different sutures found on the skull?
Coronal (between parietal bones and frontal bone)
Sagittal (between parietal bones)
Lambdoidal suture (at the back between parietal and occipital)
What are the three different cranial fossae of the skull?
Anterior
Middle
Posterior
What bones make up the anterior cranial fossae?
What part of the brain is found within it?
Contains the frontal lobe of the brain
Made by the frontal bone, ethmoid and part of the sphenoid bone.
What part of the brain is held within the middle cranial fossae?
What bones make up the middle cranial fossae?
parietal lobe
Made of the parietal, temporal, sphenoid bone
What bones make up the posterior cranial fossae?
What part of the brain does it contain?
Cerebellum
Occipital and part of parietal and temporal bone.
What cranial foramina are found in the anterior cranial fossae?
The cribriform plate
Foramen cecum
Anterior ethmoidal foramen
Posterior ethmoidal foramen
What foramina are found within the middle cranial fossae?
Superior orbital fissure
Optic canal
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
Carotid canal.
What foramina are found in the posterior cranial fossa?
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
What is the contents of the cribiform plate?
Overlaid by the olfactory bulb contains the olfactory nerves
What is found in the foramen cecum of the skull?
Usually sealed in adults
Passage of a vein from nasal cavity to sup. sagittal sinus
What is found in the anterior ethmoidal foramen?
The anterior ethmoidal artery, vein and nerve
What is found in the posterior ethmoidal foramen?
The posterior ethmoidal artery, vein and nerve.
What is the asterion?
Why is it clinically important?
An area of weakness on the skull.
Site of unification of the parietal, occipital and mastoid temporal bones.
Superficial landmark for where the transverse and sigmoidal venous sinus meet, use in anthroppoly to measure head size, used to help position hearing aids.
What are these two areas of weakness in the skull called?
Pterion
Asterion
What are the relevant foramina labelled in this image of the anterior cranial fossa?
The foramen caecum
The anterior/posterior ethmoidal foramen (left/right)
What is the content of the superior orbtial fissure?
Oculmotor, abducens, and trochlear nerve
Ophthalmic nerve (CNV1) and veins.
What is the content of the optic canal?
Optic nerve
Ophthalmic artery
What is the content of foramen rotundum?
Maxillary nerve CNV2
What is the content of foramen ovale?
Mandibular nerve CNV3 and lesser petrosal nerve
What is the content of foramen spinosum?
Meningeal branch of mandibular neve CNV3
Middle meningeal artery.
What is found in foramen lacerum?
Deep petrosal nerve
What is found in the carotid canal?
Internal carotid artery.
Label the relevant foramina on this image.
Red is optic canal
Green is superior orbital fissure
Dark blue if foramen rotundum
Light blue is foramen ovale
Label the relevant foramina in the middle crania fossa
Foramen lacerum
The carotid canal
The foramen spinolosum
What foramina are found in the posterior cranial fossa?
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
What is the content of the internal acoustic meatus?
The facial and vestibulocochlear nerve
Labyrinthine arteries
What is the content of the jugular foramen?
Internal jugular vein
The glassopharyngeal, vagus and spinal accessory nerves.
What is found in the hypoglossal canal?
The hypoglossal nerve
What is found in the foramen magnum?
Inferior end of medulla oblongata.
Spinal accessory nerves
Vertebral arteries.
Label the relevant foramina within the posterior cranial fossa.
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
From this inferior view label the relevant foramina
a - foramen magnum
B - foramen lacerum
c - carotid canal
D - foramen ovale
E - soramen spinolosum
F - external acoustic meatus
G - stylomastoid foramen
What are the different groups of muscles of facial expression?
Orbital group
Nasal group
Oral grouo
Other
What are the orbital muscles of facial expression?
The corrugator supercillii
Orbicularis oculi - orbital and palpebral portion
What is the blue muscle?
Corrugator supercilii
What is the orange muscle?
The orbital (outer) and palpebral (inner) sections of orbicularis oculi muscle.
What are the nasal group muscles of facial expression?
Nasalis
Procerus
Depressor septi nasi
What is the function and innervation of corrugator supercilii?
Supplied by temporal branches of facial nerve
Draws eyebrows inferomedially (scowl).
What is the function and innervation of orbicularis occuli?
Action - closes eyelids/ scrunches eye shut
Innervation - the temporal and zygomatic branches of the facial nerve.
What is the action an innervation of the nasalis muscle?
Action - flares the nares, transverse part (superiorly that compress and alar part inferiorly that dilates)
Innervation - buccal part of the facial nerve.
What is the action and innervation of the procerus muscle?
Wrinkles the bridge of the nose
Innervation - temporal and zygomatic branches of the facial nerve.
What is the action and innervation of depressor septi nasi?
Flares the nares - nasal septum downwards and narrows the nares.
Innervation - buccal and zygomatic branches of the facial nerve
label the relevant muscles of facial expression (the nasal group)
1 - depressor septi nasi
2 - nasalis - transverse part and alar part
3 - procerus
What muscles make up the superior oral group of the muscles of facial expression?
Levator labi superiorlis alaque nasi
Levator labii superioris
Zygomaticus minor/major
Risorius
Orbicularis oris
Buccinator
What is the function and innervation of the risorius muscle?
Function - helps produce a grin - contractions pulls corner of mouth laterally and superiorly.
Innervation - buccal branches of the facial nerve.
What is the function of the zygomaticus major and minor muscles?
Function - helps produce a smile - major - raise corners of the mouth laterally/superiorly
Minor - elevates upper lip
Innervation - zygomatic and buccal branches of the facial nerve.
What is the funcation and innervation of the levator labii superiors muscle?
Function - deepens the furrow between the nose and corner of the mouth (elevates and everts upper lip)
Innervation - zygomatic and buccal branches of the facial nerve
What is the function and innervation of the levator anguli oris?
Funcation - elevates corner of mouth, deepen furrow between nose and corner of mouth during sadness.
Innervation - zygomatic and buccal branches of the facial nerve.
What is the function and innervation of the buccinator muscle?
Action - compress cheeks - resistance against blown up cheeks
Innervation - buccal branches of the facial nerve
What is the function and innervation of the orbicularis oris?
Action - compress and protrude lips - pout
Innervation - buccal and marginal mandibular branches of the facial nerve.
What are the purple muscles shown?
The buccinator
Orbicularis oris
What is the red muscle?
Levator anguli oris
What is the black muscle?
Levator labii superioris alaequ nasi
What is the light blue muscle?
The levator labii superioris
What are the dark green muscles?
Zygomaticus major (more lateral)
Zygomaticus minor (more medial)
What is the orange muscle?
Risorius
What makes up the oral group inferior muscles of facial expression?
Mentalis
Depressor anguli
Oris
What is the function and innervation of the mentalis muscle?
Function - helps position lip when drinking, elevates +protrudes lower lip as wrinkles skin of the chin
Innervation - marginal mandibular branch of the facial nerve.
What muscles are shown on this image?
A - levator labii superioris alaque nasi
B - lavetor nasi superioris
C - levator anguli oris
D - risorius
What is the function and innervation of the depressor anguli oris muscle?
Depresses the corner of the mouth
Innervation - buccal and marginal mandibular branches of the facial nerve.
What is the function and innervation of the depressor labii inferioris muscle?
Depresses the lower lip and moves it laterally.
innervation - marginal mandibular nerve branch of the facial nerve.
Label the oral group inferior muscles of the muscles of facial expression.
Depressor anguli oris
Depressor labii inferioris
Mentalis
Please label the relevant muscles of facial expression.
Frontal belly of occipitofrontalis
Anterior auricular
Superior auricular
Occipital belly of occipitofrontalis
Posterior auricular
Platysma
What is the function and innervation of the platysma muscle?
Tenses the skin of the neck
Move the lower lip and corners of the mouth down/depresses mandible
Innervation - cervical branch of the facial nerve
What is the function and innervation of the auricular muscles?
Elevate the ear - pull in their respective direction
innervation - posterior auricular nerve and temporal branches of the facial nerve.
What is the function of the occipitofrontalis muscle?
What is its innervation?
Wrinkles the forehead/raises eyebrows and moves the scalp backwards
Innervation - posterior auricular nerve and temporal branches of the facial nerve.
What are the different motor branches of the facial nerve superficially?
Temporal branches
Zygomatic branches
Buccal branches
Marginal mandibular branches
Cervical branches
What is supplied by the temporal branches of the facial nerve?
Motor innervation to muscles of facial expression
Frontalis
Orbicularis oculi
Corrugator supercilli
What is supplied by the zygomatic branches of the facial nerve?
Motor innervation to muscles of facial expression
Orbicularis oculi
What is supplied by the buccal branches of the facial nerve?
Motor innervation to muscles of facial expression
Orbicularis oris
Buccinator
Zygomaticus
What is supplied by the marginal mandibular branches of the facial nerve?
Motor innervation to muscles of facial expression
Mentalis
Depressor labi inferioris
Depressor anguli oris
What is supplied by the cervical branches of the facial nerve?
Platysma
What is the function of the facial nerve?
Is a mixed nerve
Motor - muscles of facial expression, post belly of digastric, stylohyoid and stapedius muscle
General sensory - skin over the ear
Special sensory - taste
Parasympathetic - salivary glands and lacrimal glands.
Describe the course of the facial nerve from origin to first branches
Exits the brainstem at the pontomedullary junction - as a large motor root and a smaller sensory root
Enters internal acoustic meatus with the vestibulocochlear nerve
Travels through the petrous portion of the temporal nerve, undergoes lots of sharp bends called the genu.
Gives rise to its first few branches.
What are the first three branches of the facial nerve within the petrous portion of the temporal nerve?
Greater petrosal nerve
Nerve to stapedius
Chorda tympania
What is the function of the greater petrosal nerve?
Innervates mucous glands of mouth, nose, throat and lacrimal gland.
What is the function of the chorda tympani?
Hitchhikes on lingual - supply tase to ant 2/3 of tongue
Innervates the submandibular and sublingual salivary glands.
What is the function of the nerve to stapedius?
Motor innervation to nerve to stapedius muscle - protects the hearing apparatus (the stapes ossicles) when exposed to loud noises.
Through which structure does the facial nerve leave the skull
The stylomastoid foramen
Describe the passage of the facial nerve after leaving through the stylomastoid foramen
Gives of three motor branches: the posterior auricular nerve, nerve to posterior belly of digastic, nerve to stylohyoid muscle
Pierces the parotid gland
Terminates as five motor branches
What are the five terminal motor branches of the facial nerve?
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
What is the key muscle innervated by each terminal branch of the facial nerve?
Temporal - occipitofrontalis
Zygomatic - orbicularis oculi
Buccal - buccinator
Marginal mandibular - orbicularis oris
Cervical - platysma
Describe how an upper motor neuron lesion affects the facial nerve function?
Loss of contralateral lower face motor control
Forehead sparing (as also supplied by the unilateral side)
This is because the facial motor nucleus is split into an upper and lower nucleus - the upper portion is supplied bilaterally, the lower portion is innervated contralateral.
How does an extracranial lesion to the facial nerve present?
Is a lower motor neuron lesion
Function remains to greater petrosal, nerve to stapedius and chorda tympani
However loss of motor terminal branches - affecting both the forehead and lower face.
What arteries are mainly responsible for supplying blood to the face?
Describe its origin
The external carotid artery.
Arises at the level of the thyroid cartilage
Ascends the neck within the carotid sheath.
Also the ophthalmic artery (branch of the internal carotid) branches into the supratrochlear and supra-orbital arteries,
What are the branches of the external carotid artery?
Some Anatomists Like Freaking Out Poor Medical Students
Superior thyroid
Ascending pharyngeal
Lingual
Facial
Occipital
Posterior auricular
Maxillary
Superficial temporal
What is intramembranous ossification?
The development of bone during foetal development from within mesenchymal tissue
No cartilage involvement
Most flat bones including the skull develop this way
Requires calcium transports by blood vessels to help mineralise the bone matrix.
Mesenchyme -> osteoblasts -> collagen deposition ->osteocyte within mature matrix.
What parts of the cranium develop by intermembranous ossification?
The flat bones of the skull
The frontal bone, the parietal bones, the interparietal occipital bone and the squamous portion of the temporal bone.
What parts of the neurocranium ossify in cartilage?
The bones of the skull base - sphenoid, ethmoid, occipital, petrous and mastoid process of the temporal bone.
What are the surface markings of the middle meningeal artery?
The pterion - blunt force trauma to this portion of the skull can cause an extradural hematoma.
What is an extradural haemorrhage?
A collection of blood between the inner most layer of the skull (periosteum) and the dura matter.
Where is the motor nucleus for the facial nerve found?
In the pons
Where do the parasympathetic fibres of the facial nerve arise from?
The superior salivatory nucleus in the pons.
What nerve supplies the parotid gland?
The glassopharangyeal nerve
What glands does the parasympathetic fibres from the facial nerve innervate?
All secretory glands in the head and neck except the parotid gland.
This includes the lacrimal, submandibular, sublingual and all secreotry glands in the nasal cavity.
Where do the taste fibres of the facial nerve originate from?
What do they innervate?
Arise from the nucleus of the tractus solitarus - innervate the anterior 2/3 of the tongue.
What term is given to the sensory root of the facial nerve?
The nervus intermedius
What is the geniculate ganglion?
Why is it relevant to the facial nerve?
Found near the middle ear, in the genu, where the facial nerve makes a sharp bend
Contains the cell bodies of taste fibres from within the facial nerve.
From which pharyngeal arch is the facial nerve a derivative?
The second pharyngeal arch
What is Bell’s Palsy?
What are its common causes?
A temporary weakness or lack of weakness normally in one side of the face
Is a lower motor neuron lesion
Viral infections - HSV, varicella
Birth trauma - damage to nerve from forceps
Vitamin C deficiency - lack of neuroprotective roles.
What three layers of the skull move together?
The skin, Connective tissue, Aponeurosis.
Why is the loose areola layer considered the danger layer of the scalp?**
Contains valveless emissionary veins that allow infection to spread from the scalp to the meninges.
What is the relevance of the scalp having a vast vascular supply?
To nourish hair follicles.
Loose lots of heat from the scalp
Trauma - small lacerations can cause significant blood loss - as dense CT holds vessels open, also aponeurosis of occipitofrontalis is under tension from two bellys, if severed tension breaks and layers gape apart alongside more superficial layers.
What are emissionary veins?
Connect the extracranial venous system to the intracranial dural venous sinus
Typically found by creatine a connective between the dense connective tissue and the dural venous sinus.
Route for potential spread of infection.
What is important about the venous drainage of the scalp?**
- Follows the arterial supply - superfifical temporal, occipital, posterior articular = drainage into the internal jugular vein.
- The supraorbital vein and supratrochlear veins ->ophthalmic vein -> cavernous sinus -> potential link to sigmoid sinus (intracranial)
- Some drainage into the pterygoid plexus
- Deep connective tissue venous drainage into missionary veins into diploic veins - another point of connection between extra/intracranial drainge.
Key idea =many points of connection for infection spread.
What is the danger area of the face?
maxillary region
Above mouth
Medial orbit
Nose
Any region of the face within that gets infection - can drain and spread into the cavernous sinus - thrombosis of the cavernous sinus can press on surrounding cranial nerves - particularly related to eye movements. (CN3,4,V1,V2,6)
What is the main sensory innervation to the scalp?
Trigeminal nerve
Cervical nerve roots
What are the different branches of the trigeminal nerve that supply the sensation to the face?
Opthalmic division - the supratrochlear and the suprorbital The maxillary nerve - the zygomaticotemporal nerve
THe mandibular nerve - the auricular temporal nerve
What branches of the cervical nerve roots prodivde sensory innervation to the scalp?
Lesser occipital nerve (C2)
Greater occipital nerve (C2)
Greater auricular nerve (C2+3)
3rd occipital nerve.
Label the nerves on this image.
Zygomaticotemporal branches
Supratrochlear brnaches
Supra-orbital
Auriculartemporal
Greater auricular
C4
Lesser occipital nerve
Third occipital nerve
Greater occipital nerve.
Describe the lymphatic drainage of the scalp.
Superficial vessels drain lmph from the Scalp, face and neck into superficial ring of lymph nodes at junction of the head and neck.
Drain into deep (cervical) lymph nodes parallel to the internal jugular vein within the carotid sheath
Converge to form the jugular lymphatic trunks.
What is the supraorbital notch?
Portion of the frontal bone
Medial and superior to the orbit margin
For passage of the supraorbital vein, artery and nerve to the forehead.
What is the squamous suture of the brain?
Separates the temporal and parietal bones
