Head and Neck Flashcards
What are the borders of the anterior and posterior triangles of the neck?
Anterior -
medially imaginary sagittal line, superiorly lower border of mandible, lateroposteriorly medial edge of sternocleidomastoid
Posterior -
superomedially lateral edge of SCM, inferiorly middle 1/3 of clavicle, posteriorly trapezius
Where would you insert a central line?
Subclavian vein or internal jugular vein in posterior triangle of the neck or femoral vein
List the fascial layers of the neck.
Deep investing fascia of the neck Subcutaneous fascia Pre-tracheal Pre-vertebral Carotid sheath
What 4 triangles can the anterior triangle of the neck be divided into?
Carotid, submental, mandibular and muscular
What 2 triangles can the posterior triangle of the neck be divided into?
Occipital and subclavian
What is the function of having multiple fascial planes in the neck?
To allow easy independent movement of structures during swallowing and movements of the neck. It also usually contains infections within the compartments formed.
What is the retro-pharyngeal space and what is its relevance?
The potential space between the pretracheal and prevertebral fascias. It extends down to the diaphragm and thus can become a conduit for infection in the neck to spread to the chest, and potentially cause life-threatening mediastinitis. However this is extremely rare.
What are the borders of the carotid triangle and what are its contents?
Borders: superiorly - posterioir belly of digastric posteriorly - medial border of SCM inferioirly - superioir belly of omohyoid Contains: bifurcation of the carotid artery internal jugular vein Hypoglossal and Vagus nerves
Where would you palpate a carotid pulse?
Between SCM and trachea, roughly at level of cricoid cartilage with the patient’s head gently tilted to one side. Do not go above the thyroid cartilage to avoid inadvertently massaging the carotid sinus.
How do you measure JVP? Which jugular vein is inspected and why?
Position patient reclined at 45’ with head turned away.
Look for pulsation between sternal and clavicular heads of SCM (can check if arterial by palpation)
Measuring the vertical height from sternal angle to the top of the pulse. Add 5cm to obtain the right heart filling pressure in cm of water. A pressure above 9 = elevated.
Can exaggerate pulsations be eliciting hepato-jugular reflux.
Internal jugular vein - more accurate
What are the pharyngeal arches?
A system of mesenchymal proliferations in the neck region of the embryo
Where can branchial cysts be located and how do they develop?
Anywhere along the anterior border of the SCM. They develop if the cervical sinus (2nd branchial cleft) is not obliterated during development.
Briefly describe diGeorge syndrome.
Failure of development in the 3rd & 4th Ph pouches: CATCH 22
Cardiac defects
Abnormal facial appearence
Thymic hypoplasia
Cleft palate
Hypocalcaemia (due to absence of parathryoid glands)
Due to Deletion on chromosome 22
What is Treacher Collins syndrome?
Causes hypoplasia of mandible and facial bones
It is an example of a first arch syndrome (failure of colonisation of the 1st Ph arch with neural crest cells)
Inhertited autosomal dominant
What are the branches of the arch of the aorta?
Brachiocephalic trunk
Left common carotid
Left subclavian
What is the clinical relevance of the bifurcation of the aorta (3 things)?
Location of carotid body
Location of carotid sinus
Common site of atheroma formation
As they travel in the neck, where are the vertebral arteries located?
Within the transverse foramina in C6-1
Which 2 sets of arteries supply the brain?
Internal carotid arteries and the vertebral arteries
In which layer of the scalp is its blood supply located, and so why do scalp injuries tend to bleed profusely?
Dense connective tissue layer, because this limits contriction plus wounds are often help open by the epicranial aponeurosis
What are the dural venous sinuses and where are they located?
Endothelium lined spaces between the periosteal and meningeal layers of dura
Located posteriorly in the cranial cavity:
superficial sagittal sinus superfically
inferior sagittal sinus deep
What are the layers of the scalp and so what is an extra-dural haemorrhage?
Skin Connective tissue (dense) Aponeurosis Loose connective tissue Periosteum An extra-dural haemorrhage is where a collection of blood forms between the skull and the periosteum
What is the risk of a strong blow to the temple and why?
Location of the pterion which is a relatively weak area of the skull where 4 bones join over which the middle meningeal artery passes. If this artery ruptures it can cause an extradural haemorrhage which can cause increased intracranial pressure.
How might a scalp infection become dangerous?
The veins that drain the scalp connect to the diploic veins of the skull through various valveless emissionary veins which them drain into the dural venous sinuses. Thus infections can spread from the scalp to the cranial cavity and affect the meninges.
What is the “danger triangle” of the face and why is it called so?
Bounded by bridge of nose and corners of mouth
Infections here may result in thrombophlebitis of the facial vein after which the infected clot can travel into the intracranial venous system and potentially cause cavernous sinus thrombosis. Infections can also spread to the dural venous sinuses and affect the meninges.
What is the cavernous sinus and where is it located?
A plexus of extremely thin walled veins located on the upper surface of the sphenoid
Which cranial nerves may be affected by cavernous sinus thrombosis?
Typically abducens
But also Occulomotor CNIII ,Trochlear CN IV, and ophthalmic and maxillary branches of the Trigeminal CNV2 and 3
Mnemonic for contents of cavernous sinus = OTOM CAT
Where C is for internal carotid artery
What is the function of the lymphatic system?
Allows small proteins, damaged cells and other components of tissue fluid that can’t be reabsorbed to be drained, thus preventing oedema.
Give 6 causes of chronic lymphoedma.
Removal of lymph nodes Chronic enlargement of lymph nodes Certain infections Damage to lymphatics due to radiotherapy etc Lack of limb movement Congenital - Milroy syndrome
How would you examine the lymph nodes of the head and neck?
Palpate under chin for sub mental, under angle of jaw for submandibular, in front of ear for preauricular, behind ear for post auricular, at back of head for occipital, down neck for anterior and posterior cervical chains and in supraclavicular fossa for those nodes (L for Virchows node)
What is Waldeyer’s ring?
A ring of nodules of MALT surrounding superior pharynx
What features of typical cervical vertebrae differentiate them from thoracic and lumbar vertebrae?
Bifid spinous process
Transverse foramina
Triangular vertebral foramen
Which cervical vertebra is most easily palpable?
C7
How do atlas and axis fit together and what movements do they allow?
Odontoid peg of axis inserts between anterior arch and transverse ligament of atlas
Allows rotation of head in vertical plane (nodding yes - atlas) and in transverse plane (shaking no - axis)
What cervical spine fracture is likely to occur due to a fall head first from a height?
(Name and Describe)
Burst or Jefferson fracture
2 breaks in anterior arch of atlas and 2 in posterior arch
What is a Hangman’s fracture and how might it occur? (A likely cause)
Paired fracture in axis vertebra, located on both sides just posteriorly of the transverse processes
Occurs due to hyperextension of the head of the neck eg falling onto chin or in a RTA
Describe the structure and function of the cranial sutures in the neonate.
Coronal suture across skull anteriorly, lamboid suture posteriorly, joined by sagittal suture. Unlike adults also have metoptic suture within frontal bone and these sutures are wide containing thick connective tissue matrix.
Allows the bones to push together and temporarily interlock during birth to protect brain during childbirth.
What are bregma and lamda?
Membranous island gaps between the cranial sutures
What features of the skull facilitate its protective function? (Remember layers)
Consists of flat bones which are dense and thus strong
Has 2 layers of compact bone (outer and inner - middle is spongy)
The foramina of the skull allow passage of neurovasculature and lymphatics in and out of the the skull. What is a disadvantage of the skull having foramina?
Makes the cranium floor weak thus it is likely to fracture in high energy impacts to the head
Where is the ethmoid bone located and what is a likely consequence of a fracture?
Midline of anterior cranial fossa
Anosmia (loss of sense of smell)
Where is the mastoid part of the temporal bone and what does it contain?
Behind pina
Mastoid air cells
How can otitis media lead to meningitis?
Otitis media can lead to infection in the mastoid air cells of the temporal bone (mastoiditis) which can then spread to the middle cranial fossa where it can spread to the meninges.
What are the possible consequences of a fractured temporal bone?
Vertigo and other balance problems
Sensorineural, conductive or mixed hearing loss
Facial paralysis
CSF fistula
Describe the parts of the embryo at week 4 of gestation that will later become the face.
Frontonasal prominence
Paired maxillary prominences and paired mandibular prominences both from 1st Ph arch
From which embryological tissue does the facial skeleton originate?
Neural crest (of the 1st pharyngeal arch)
Describe how cleft lip and cleft palate may develop.
Embryological failure of fusion of medial nasal prominence and maxillary prominence combined with failure of palatine shelves to fuse in the midline.
What might low set ears indicate? Explain how they might develop.
A chromosomal abnormality
The auricles of the ears develop from proliferation within the 1st and 2nd pharyngeal arches, initially developing as auricular hillocks in the neck which then ascend as the mandible grows. Any cause of failure of the ascent would cause low set ears.
What are the features of foetal alcohol syndrome and how common is it?
Smooth philtrum, low nasal bridge, epicanthal folds, small eye openings, underdeveloped jaw, flat mid face
Can cause neurodevelopmental delay
Fairly common - 1/100 births
Name the cranial nerves.
Oh oh oh to touch a female’s vagina gives Verne a hallucination:
Olfactory, Optic, Occulomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Vagus, Accessory, Hypoglossal
Which cranial nerves aren’t technically nerves and why?
Olfactory and Optic
They are brain tracts
Where are the jugular foramen and which nerves pass through it?
Paired - one on each side, lateral to occipital condyles on base of the skull
Glossopharyngeal IX, Vagus X and Accesorry XI
Which foramina do the 3 branches of the trigeminal nerve pass through?
Ophthalmic branch - sup orbital foramen
Maxillary branch - foramen rotundum
Mandibular branch - foramen ovale
(Some Random (h)’Ole)
How would you test the cranial nerves?
Olfactory - orange or coffee smell
Optic - Visual fields and acuity. Pupillary response - direct light reflex, consensual, accommodation. Fundoscopy
Occulomotor, Trochlear and Abducens - inspect resting gaze, “follow my finger” ask about double vision, look for nystagmus
Trigeminal - light touch in ophthalmic, maxillary and mandibular regions. Palpate temporalis and masseter, move jaw side to side
Facial nerve - raise eyebrows, screw up eyes, smile and show teeth, blow out cheeks
Vestibulocochlear- simple test of hearing, Rinne’s, Weber’s
Glossopharyngeal & Vagus - cough, soft palate movement (“ah”), gag reflex if necessary
Accessory - shrug shoulders, turn head side to side
Hypoglossal - wasting or fasiculations? tongue movement, protrude tongue
List some causes of anosmia
Trauma to cribriform plate
Meningitis
Upper respiratory tract infection
Describe the pupillary light reflex
The afferent limb (within the Optic nerve) relays stimulus from the retina to Edinger Westphal nucleus from which the efferent limb (within the Occulomotor nerve) relays the stimulus to cause direct (Ie in stimulated eye) and consensual (ie in ipsilateral eye) pupillary constriction.
A lesion in which cranial nerve would cause ptosis with a “down and out” pupil? Why is this often associated with a pupil dilation on the affected side?
What are the main causes of this?
Occulomotor
Parasympathetic fibres controlling sphincter papillae and cilary muscles hitchhike on the nerve
Increased intracranial pressure, aneurysm of posterior cerebral artery, cavernous sinus infection, trauma
In which cranial nerve does a “false localising sign” imply a lesion in and why?
Abducens
It is the first nerve affected by raised intracranial pressure
Which nerve is responsible for the corneal reflex?
Trigeminal nerve
In which structure does the facial nerve divide into its branches?
Parotid gland
What are the branches of the facial nerve?
Two Zulus Buggered Mmy Cat:
Temporal, Zygomatic, Buccal, Marginal mandibular, Cervical
What are the functions of the facial nerve?
Supplies muscles of facial expression, stapedius, posterior belly of diagastric muscle and stylohyoid muscle
Special sensory to anterior 2/3 of tongue (taste)
Supplies lacrimal and salivary glands (plus many other glands of head and neck)
What is a vestibular schwannoma and what symptoms can it cause?
Benign tumour of the Schwann cells covering the Vestibulocochlear nerve
Causes hearing and balance problems and if large can cause headaches with blurred vision, one sided facial numbness/pain due to compression of facial nerve and one sided limb and coordination problems
Which nerves are responsible for the gag reflex?
Glossopharyngeal- sensory
Vagus - motor
What is the sensory innervation to the carotid sinus?
Glossopharyngeal nerve!
What does the spinal accessory nerve do?
Motor supply to sternocleidomastoid and trapezius muscles
If there is damage to the innervation of the tongue, to which side will it deviate?
Towards the side of the lesion
Describe the sensory innervation of the face
Supplied by Trigeminal nerve:
Ophthalmic branch - central forehead and centre of nose
Maxillary branch - temples, cheeks and sides of nose, upper lip
Mandibular branch - jaw line from ear to ear, chin, bottom lip
What triad of symptoms does Horner’s syndrome encompass?
Partial Ptsois - partial drooping eyelid
Miosis - excessively contracted pupil
Anhydrosis - no sweating on that side
Describe the aetiology and pathology of Horner’s syndrome
Unilateral stretching or damage of sympathetic fibres especially sup. cervical due to trauma to sympathetic trunk or ganglia in the neck, spinal nerve lesions, pancoast tumour (apical lung tumour)
Ptsois is partial as only superior tarsal muscle is paralysed
What are the 4 parasympathetic ganglia in the head and neck and what do these supply?
Cilary - sphincter papillae and cilary muscles
Pterygopalatine - lacrimal gland, glands of nose, palate and nasopharynx
Submandibular - submandibular, sublingual and other glands of oral cavity
Otic - parotid gland and glands of oropharynx and posterior 1/3 of tongue
Which bones contribute to the orbit?
Frontal, Zygomatic, Maxilla, Ethmoid, Sphenoid and Lacrimal
In which bone is the superior orbital fissure located?
Sphenoid
Which nerves pass through the superior orbital fissure?
Occulomotor nerve (frontal, superior and inferior branches)
Trochlear nerve
Nasocilary branch of Ophthalmic nerve
Abducens nerve
Where is the optic canal located and what travels within it?
Within the sphenoid bone
The optic nerve and ophthalmic artery
Which nerve supplies most of the muscles supplying the eye?
(Remember LR6 SO4 R3)
CN III - Occulomotor
What is the innervation of the lateral rectus muscle?
(Remember LR6 SO4 R3)
CN VI - Abducens
Which muscle of the eye does the Trochlear nerve supply?
(Remember LR6 SO4 R3 and Trochlear nerve is CNIV)
Superior oblique
Which muscle is supplied by fibres from the superior cervical ganglion?
Superior tarsal muscle in the eyelid
Which muscles allow you to open and close your eyes?
Levatator palpaebrae superioris - retracts and elevates eyelid
Orbicularis oculi - shuts eyes
From which branch of the Internal Carotid Artery does the central retinal artery originate from?
The ophthalmic artery
What would be the result of central retinal artery occlusion and why?
Instant and total blindness as it is an end artery
What clinical sign can be seen on fundoscopy in central retinal artery occlusion?
Central cherry red spot
Why is there a risk of infection in the eye tracking back into the cranial cavity?
Central retinal vein that drains the eye drains into superior ophthalmic vein which then drains into the cavernous sinus which is found within the cranial cavity.
Why does your nose run when you cry?
Tears run down nasolacrimal duct into the nasal cavity
Where is the lacrimal gland located?
Under the lateral side of the eyebrow, above the eyelid
What are the differences between a stye and a Meibomian cyst?
A stye forms due to an infection some of the cilary glands, is usually painful and requires antibiotics. While a meibomian cyst is due to blocked tarsal glands (located further up the eyelid), is usually painless and can be treated with a hot compress.
Which areas of the eye would you expect to be inflamed in conjunctivitis?
The surface if the eyeball and the inner surface of the eyelid (bulbar and palpebral conjunctiva respectively)
What is the function of the eyelid?
Protect eye from injury, excessive light and dryness
Which layer of the eyeball is responsible for the “red eye reflex”?
The choriod - vascular layer between sclera and retina that supplies retina
What is the difference between the posterior chamber and the posterior segment of the eye?
Posterior chamber is the posterior part of the anterior segment at the front of the eye behind the ciliary muscle
While the posterior segment is that behind the posterior chamber and contains vitreous humour
What is the other name for the posterior segment?
The vitreous chamber
Where is the anterior chamber located?
At the front of the eyeball between cornea and ciliary muscles
How can photophobia be a sign of meningitis?
Optic nerve is a brain tract thus has meningeal covering and so can be affected by meningitis
What are the 3 main layers of the eyeball?
Outer fibrous layer
Middle vascular layer
Inner layer
What are the symptoms of retinal detachment?
Flashes of light, “floaters”, blurred or distorted vision -> blindness
Where is the aqueous humour? What produces it?
Within the anterior segment of the eye
Produced by ciliary body
What pathological changes in the eye result in the symptoms of cataracts?
Increasing hardening, flattening and opacity of the lens of the eye leads to vision becoming increasingly blurred and dazzled
What are the risk factors for cataracts?
Age
Smoking
Diabetes
Sunlight
What is papilloedema?
An optic disc swelling that occurs due to raised intracranial pressure
What are the signs of papilloedma?
Elevated margins and congested vessels
What causes papilloedema?
Causes of raised intracranial pressure such as a brain tumour, some medications, rarely extreme dehydration
What is the clinical term for double vision?
Diplopia
What is surgical / subcutaneous emphysema?
Collection of air in subcutaneous tissue
What is proptosis?
Abnormal protrusion of eyeball - “starey eyes”
What signs are associated with an Occulomotor nerve (CNIII) palsy?
Ptosis, “down and out” eye (pupil positioned inferiorly and laterally) and dilated pupil
Why can palsy of CNVI cause binocular horizontal diplopia?
CNVI is the Abducens nerve which innervates the lateral rectus muscle allowing abduction of the eyeball such as occurs when looking sideways. This will mean that when looking sideways, eyes are misaligned and images detected will not be superimposable and so 2 separate images will be perceived by the visual cortex causing double vision.
Palsy of which cranial nerve can present with a head tilt, and why?
Trochlear nerve (CNIV) - innervates superior oblique muscle of the eye which allows intortion of the eye - tilting of the head is an attempt to overcome these problems with eye rotation caused by palsy of the nerve
What are the 3 key questions in a case of orbital fracture?
(Think what is sight threatening)
Is optic nerve compromised?
Is there a risk of retrobulbar haemorrhage?
Is there an injury to the globe?
Besides the 3 key questions, what other questions should you also consider in the case of orbital fracture?
Are other facial bones involved?
Is there a risk of foreign bodies in the eye?
What are the signs and symptoms of an orbital fracture?
Lid swelling, double vision (diplopia), reduced vision
Restriction of eye movements, reduced visual field and vision, enophthalmos (sunken eye)
What sign may you see on scans in the case of orbital fracture?
Eye protruding out of orbital cavity through broken bone
What is the most commonly fractured bone in orbital fractures?
Maxillary
What are the clinical signs of ethmoidal (medial orbital) fractures?
Horizontal diplopia, surgical emphysema
What are the symptoms of thyroid eye disease?
Ocular irritation, redness, double vision (diplopia)
How do you evaluate the severity of thyroid eye disease?
Use NOSPECS method: 0 No symtoms or signs 1 Only symptoms, no signs 2 Soft tissue involvement (eg lid oedema) 3 Proptosis 4 Extra-ocular muscle involvement 5 Corneal ulceration 6 Sight loss
What are the signs and symptoms of orbital cellulitis?
Inflamed eyelids, pain, sticky discharge
Fever, painful/restricted eye movements, decreased vision and colour vision, RAPD, proptosis if severe
Which signs of orbital cellulitis are not associated with other inflammatory diseases?
RAPD, decreased vision and colour vision, proptosis, painful/restricted eye movements (i.e. all but fever)
What is an important potential clinical consequence of a capillary haemangioma in a child?
Can affect sight development
What is dacryoadenitis?
Lacrimal gland irritation - potential cause of an orbital mass lesion
Why is it important to consider Wegener’s in the case of an orbital mass lesion?
Wegener’s (necrotising granulomatous vasculitis) has systemic implications
List 7 causes of orbital mass lesions
Wegener’s (necrotising granulomatous vasculitis)
Dacryoadenitis
Pseudo-tumour (idiopathic orbital inflammatory disease)
Dermoid cyst
Mucocele
Capillary haemangioma
Cavernous haemangioma
Describe the innervation of the external ear
Auriculotemporal nerve - superomedial incl crus of helix
Auricular branch of the Vagus nerve - concha
Great auricular nerve - lateral lobe, helix except most medial part and lateral part of antihelix
What is the ear-cough reflex and why does it occur?
Triggering of gag/cough reflex by irritation to concha of external ear in the area innervated by the branches of the vagus nerve, irritation is referred along other branches of vagus including efferent branch of cough/gag reflex
What glands does the epithelium of the external acoustic canal have?
Ceruminous and sebaceous glands (produce cerumen - earwax)
How do the sensory fibres of the Vestibulocochlear nerve reach the inner ear?
Through the internal acoustic meatus within the petrous temporal bone
What fluid is contained within the membranous labyrinth of the inner ear?
Endolymph
Where is the perilymph located, and what function of the ear does it support?
Located within the bony labyrinth
Supports hearing
What is the difference between the pars flaccida and pars tensa of the tympanic membrane?
Pars tensa has radial and circular fibres, pars flaccida has neither
What is the innervation of the tympanic membrane?
External surface: mainly Auriculotemporal nerve (branch of CNV3) and some Auricolotemporal branch of Vagus
Internal surface: Glossopharyngeal nerve
What separates the tympanic and cranial cavities?
A thin layer of bone called the tegmen tympani
What forms a communication between the middle ear and the nasopharynx?
The Eustachian (pharyngotympanic) tubes
Name the auditory ossicles and describe how they are arranged
Malleus - articulates with -> Incus articulates with -> Stapes
Name the 2 muscles of the inner ear
Tensor tympani and Stapedius
What is the function of the round window of the cochlea?
Allows movement of fluid within the cochlea, which in turn allows hair cells of basilar membrane to move and audition to occur
Where is the round window in the inner ear located?
At the basal turn of the cochlea
Where does the stapes attach to?
The membrane covering the oval window in the lateral vestibule
What number of semi-circular canals are there in the inner ear? Describe their arrangement
3, set at right angles to each other
What lies between the semi-circular canals and the cochlea?
The vestibule of the inner ear
How would you examine the tympanic membrane?
With an otoscope, gently pulling ear upwards and back to straighten external auditory canal
What is associated with congenital deformities of the pina?
Chromosomal syndromes and thus other malformations
What is a perichondrial pina haematoma?
A build up of blood between the perichrondium and cartilage of the pina due to trauma causing ripping of the perichrondial vessels
What can a perichrondrial pina hematoma lead to and why?
Cauliflower ear as the resulting separation of cartilage from its bloood supply will cause pressure necrosis resulting in scarring if not treated
What are the causes of tympanic perforation?
Trauma or secondary to infection (causing pressure necrosis)
Explain an important potential clinical consequence of otitis externa in an immunocompromised individual
Can lead to necrotising otitis externa where infection (often pseudomonas aeuginosa) spreads to bone
Describe how “glue ear” can develop after an acute ear infection
Thick effusions behind the tympanic membrane
Can develop after acute otitis media if it causes prolonged tympanic retraction
Which species of bacteria are implicated in the aetiology of acute otitis media?
Pneumooccus
Haemophilus
Streptococci
What rare complication of otitis media causes swelling behind the ear?
Mastoiditis
How can otitis media lead to facial drooping?
If the causative infection causes damage to CNVII (Facial nerve) which runs through the middle ear to then supply the muscles of facial expression
What are the classical 4 symptoms of Meniere’s disease?
Vertigo
Tinnitus
Hearing loss
Aural fullness
Give 3 examples of locations from where pain may be referred to the ear
Nasopharynx
Teeth
Jaw and Temporomandibular joint
What is otalgia?
Ear ache
What is the cause of benign positional paraoxysmal vertigo
Otolith displacement
Describe the aetiology of cholesteatoma
Negative ear pressure -> retraction pockets -> dead skin cells accumulate and become necrotic, forming a mass known as a cholesteatoma
Why is a cholesteatoma called so?
It behaves somewhat like a malignancy in that it causes the erosion of middle ear and bone due to lytic enzymes
List 3 clinical consequences of a cholesteatoma
Painless otorrhea - the hallmark symptom
Conductive hearing loss
Meningitis (and other CNS complications)
What are the functions of the nose?
Humidification and filtering
Olfaction and respiration
Drain and eliminate paranasal sinus and nasolacrymal duct secretions
What is the limen nasi?
The border between the vestibule, which is lined by skin, and the nasal cavity proper
What are the alae? (singular: ala)
The ridges forming the lateral boundaries of the nostils
What bones contribute to the nose?
Frontal, Nasal, Ethmoid, Sphenoid, Vomer, palatine process of Maxilla, horizontal process of Palatine bone
*What may happen if the cribriform plate is fractured?
Anosmia (loss of sense of smell)
*How can a nasal fracture lead to a saddle nose deformity?
Septal deviation and haematoma -> avascular necrosis
What are the choanae?
The two posterior openings/apertures of the nasal cavity into the nasopharynx
What type of epithelia lines the nasal cavity?
Respiratory - pseudostratified columnar ciliated epithelium with goblet cells
What are conchae and what is their function?
Protrusions on the lateral wall of the nasal cavity that create turbulent airflow, allowing the mixing of air, facilitating the humidifcation and warming of inspired air
Which structures drain into the nasal cavity?
The paranasal sinuses
Lacrimal apparatus
Middle ear
What is the spheno-ethmoidal recess?
The space between the superior turbinate and the roof (cribriform plate) of the nasal cavity (sphenoid sinuses drain here)
What are the superior, middle and inferior meatuses of the nose?
The spaces between the turbinates / conchae
*Branches from which 3 arteries of the face anastomose to form the blood supply to the nasal cavity?
The facial artery, the maxillary artery and the ophthalmic artery
*Name the arteries supplying the nasal septum
Posterior and Anterior ethmoid arteries
(branches of) Superior labial artery
Greater palatine artery
Sphenopalatine artery
*What is Kiesselbach’s (Little’s) area?
An area of rich anastomoses on the anterior nasal septum that is the commonest site of ruptured vessels in epistaxis (nose bleeds)
*What is epistaxis?
Nosebleed
*Branches originating from which cranial nerves innervate the nose?
CNI - Olfactory
CNV1and2 - Opthalmic and Maxillary divisions of Trigeminal
What nerves supply the external nose?
Infraorbital nerve (CNV2) External nasal nerve (CNV1)
Name the nerves that supply to nasal mucosa
Nasopalatine nerve
branches of Greater palatine nerve
branches of Nasocilary nerve
What is the innervation to the paranasal sinuses?
Branches of Opthalmic (CNV1) and Maxillary (CNV2)
Why does chronic sinusitis tend to present after puberty?
Sinuses small, or not present in case of frontal, at birth and enlarge around puberty
Name the paranasal sinuses and describe their locations
Frontal - forehead
Ethmoidal - between orbit and nasal cavity
Sphenoid - related to pituitary and middle cranial fossae
Maxillary - cheeks
How can tooth ache be linked to sinusitis?
Sensory innervation of maxillary sinus, which is the most commonly inflamed, includes branches of alveolar nerves thus pain can be referred to the teeth (and the skin of cheek and upper jaw)
How can you ascertain if tooth ache is linked to sinusitis?
The pain will be worse on leaning forward
Describe the drainage of the maxillary sinus
Upwards into posterior middle meatus
How could inflammation in the sphenoid sinus potentially affect endocrine function?
It is anatomically related to the pituitary gland
How can an infection in the ethmoidal sinus be dangerous to the eye?
Posterior ethmoidal air cells are located near orbit, near to optic canal, and so, if drainage is blocked, infections can break through into orbit and potentially damage the optic nerve causing blindess
What are the symptoms of rhinitis?
Increased secretions - runny nose
Swelling - stuffy nose
Headaches
Sneezing
Describe the common aetiology of sinusitis
Often viral with secondary bacterial infection - S. pneumoniae, H. influenzae
How do rhinitis and sinusitis cause the symptom of headaches?
Sensory innervation is via the Trigeminal nerve which also supplies meninges etc. and so pain can be referred to cause a headache
*Resp. What are the main causative organisms of upper respiratory tract infections?
Rhinovirus, Coronavirus, Influenza, Parainfluenza, Respiratory Syncitial Virus
Describe the two main types of nose bleeds
Anterior - bleeding from Kiesselbach’s plexus
Posterior - bleeding from sphenopalatine artery
What are the main causes of nose bleeds?
Local - infections, trauma, mucosal drying
Systemic - hypertension, coagulation defects, NSAIDs
What is the epidemiology of nose bleeds?
Bimodal distribution - common in young children and older people
How would you first manage a nose bleed?
Pinch soft part of nose just below nasal bones and lean forward for 20 mins, apply ice if possible
What treatments are indicated if initial (first aid level) management of a nose bleed is unsuccessful?
Cautery -> anterior packing with rapid rhino or merocel -> posterior packing with a female / Foley catheter and then anterior pack as well -> ligation of SPA, maxillary, external carotid arteries
Describe and explain the main signs of a “pupil sparing” Occulomotor nerve lesson
Lesion of just the Occulomotor nerve itself,
causing ptosis due to denervation of levator palpaebrae superoris,
and “down and out” position of eye due to unopposed actions of lacteral rectus and superior oblique muscles (only muscles of the eye not supplied by Occulomotor n)
Why can a lesion of the Occulomotor nerve cause pupil dilation?
Autonomic parasympathetic fibres from Edinger-Westphal nucleus “hitchhike” on Occulomotor nerve so are often also affected by lesions affecting the Occulomotor nerve due to their proximity. These fibres supply the sphincter pupillae muscle of the eye, denervation of which causes pupil dilation due to unopposed action of dilator pupillae muscle.
What is mydriasis?
A “blown” or abnormally dilated pupil
What are the branches of the Occulomotor nerve and what do they supply?
Superior branch supplies sup. rectus and levator palpabrae superioiris
Inferior branch supplies inf. rectus, inf. oblique and medial rectus
Name the 3 nerve roots of the Trigeminal nerve
Opthalmic, Maxillary and Mandibular
Which nerve is responsible for the corneal reflex?
Nasociliary branch of Opthalmic branch of Trigeminal nerve
What types of nerve fibres does the Trigeminal nerve carry?
Sensory, motor and sympathetic
What types of nerve fibres does the Facial nerve (CNVII) carry?
Sensory, special sensory, motor and autonomic
What part of the tongue does CNVII innervate?
Anterior 2/3
When can unilateral facial paralysis be forehead sparing and why?
In upper motor neurone lesions in facial nerve CNVII, as frontalis muscle receives bilateral innervation
What is Bell’s Palsy?
Idiopathic CNVII palsy, common, symtoms usually temporary
How can the facial nerve be damaged?
Parotitis, tumours of parotid gland, parotidectomy
Forceps delivery
Inflammation, usually due to infection
Typhanectomy
Surgical procedures of infratemporal fossa
What are the borders of the oral cavity?
Hard palate and soft palate
Teeth
Imaginary line between left and right palatoglossal folds
Mylohyoid muscle (inferiorly)
Where exactly are the palatine tonsils located?
Between the anterior and posterior tonsillar pillars of the oropharynx (i.e. the palatoglossal and palatopharyngeal arches)
What is the intermaxillary suture and what is its embryological origin?
Central sagittal join in bones of hard palate, leaving a ridge down the majority of the roof of the mouth, formed by fusion of palatal shelves of maxillary process
Name the muscles of the soft palate and describe their overall function
M. uvulae M. levator veli palatini M. tensor veli palatini M. palato pharyngeus M. palato glossus Pull on uvula and coordinate swallowing etc.
Describe the normal appearance of the gingival mucosa
Paler than adjacent alveolar mucosa
Describe the nature and potential consequences of being “tongue tied”
Abnormally large lingual frendulum can cause problems with feeding and speech
Where do the sublingual and submandibular salivary glands open into the oral cavity?
At the sublingual and submandibular papillae either side of the lingual frendulum under the tongue
Where does the parotid gland open into the oral cavity?
Into buccal mucosa above 2nd molar
What might a painful mass located under the tongue be?
Salivary calculi (stone)
Describe the naming of the teeth
Upper / lower?
Left / right?
Central incisor, lateral incisor, canine, 1st 2nd pre-molar or 1st 2nd or 3rd molar ?
Which nerves innervate the muscles of the tongue?
Hypoglossal nerve - all muscles except..
Palatoglossus muscle - supplied by Vagus nerve
Describe the sensory innervation to the tongue
Small central area posteriorly - Internal laryngeal nerve (CNX)
Rest of posterior 1/3 - Glossopharyngeal nerve for sensory and special sensory
Anterior 2/3 - Lingual nerve (CNV) for sensory, Chorda tympani (CNVII) for special sensory
Overlapping region 2/3 posteriorly has mixed supply of Glossopharyngeal, Lingual and Chorda tympani
Name and describe the locations of the extrinsic muscles of the tongue
Genioglossus - arises from the mental symphysis and inserts into the dorsum of the tongue
Styloglossus - arises from the hyoid bone and inserts into the side of the tongue
Hypoglossus - arises from the hyoid bone and inserts into the side of the tongue
Palatoglossus - arises from the palatine aponeurosis and inserts broadly across the tongue
Name and describe the actions of the intrinsic muscles of the tongue
Superior and Inferior longitudinal - make tongue short and thick and retract tongue
Vertical and transverse - make tongue long and narrow, protrude tongue
Describe the common appearance of the tonsils in tonsillitis
Swollen, with white spots of exudate within crypts
What is quinsy and how should it be managed?
Peritonsillar abscess - needs surgical draining
What type of cartilage does the temporomandibular joint contain? and Tob Describe the features of this cartilage
Fibrocartilage!
Contains fibroblasts, few chrondrocytes, type 1 & 2 collagen with coarse fibres parallel to direction of stress
Describe the structural features and function of the articular disc of the TMJ
Concavo-convex upper surface
Concave lower surface
Thinner centrally and thicker at the edges
-> Facilitates articulation of the poorly aligned temporal and mandibular bone
How is the stability of the TMJ increased?
By support from various ligaments - particularly the temporomandibular ligament, sphenomandibular ligament and stylomandibular ligament
How is posterior, anterior or inferior displacement of the TMJ limited?
Posterior - posterior glenoid tubercle
Anterior - articular tubercle
Inferior - the accessory ligaments - sphenomandiular and stylomandibular
Describe the muscles and movements involved in opening the mouth
Lateral Pterygoids pull condyles forward
Digastric muscles pull chin down and back
Describe the muscles and movements involved in closing the mouth
Posterior fibres of Temporalis retract the mandible
Rest of Temporalis, Masseter and the Medial Pterygoids elevate the mandible
What is bruxism?
Clenching the jaw and grinding of teeth especially during sleep
How common is TMJ pain?
Very common - 25% of population (though only a small number of these seek medical help)
What symptoms suggest arthritis of the TMJ?
Pain, stiffness, feelings of “joint grinding”
What are the boundaries of the infratemporal fossa?
Lateral - Ramus of mandible Medial - Lateral pterygoid plate of sphenoid Anterior - Posterior surface of maxilla Posterior - Carotid sheath Roof - Greater wing on sphenoid Floor - Medial pterygoid muscle
Describe the arterial contents of the infratemporal fossa and their clinical relevance
Maxillary artery branching into Middle Meningeal Artery
Superficial temporal artery passes NEXT TO fossa
Injuries to these can lead to considerable bleeding
Describe the venous contents of the infratemporal fossa
Pterygoid venous plexus
Maxillary vein
Middle meningeal vein
Which nerves pass through the infratemporal fossa?
Mandibular nerve - branches within fossa
Chorda tympani
Otic ganglion
What areas does an inferior alveolar nerve block anaesthetise?
Mandibular teeth and lower lip
Why may tumours in the infratemporal fossa be advanced at presentation?
Fossa provides potential space into which tumours can grow quite large before becoming symptomatic
Where is the pituitary gland located?
Within pituitary fossa of sphenoid bone, near to hypothalamus
Describe the embryological origin of the pituitary gland
Anterior - ectoderm from Rathke’s pouch
Posterior - neuroectoderm from infundibulum (outgrowth of forebrain)
Which pharyngeal arches does the tongue develop from?
1, 2, 3 and 4
How is the nature of the sensory innervation of the tongue explained by its embryological origin?
Anterior 2/3 derived from Ph arches 1 and 3 - supplied by CNV and CNIX - the cranial nerves of the 1st and 3rd arches respectively
Posterior 1/3 derived from Ph arches 3 and 4 - supplied by cranial nerves corresponding to those pharyngeal arches CNIX and CNX
(NB Papillae - special sensory from Facial nerve - nerve of second arch)
Where does the primordium of the thyroid gland develop?
In the floor of the pharynx
Why do some people have a pyramidal lobe of their thyroid gland?
Remnant of embryological thyroglossal duct which normally regresses
What is the embryological origin of the parafollicular cells of the thyroid gland? and What is their function?
Ultimobranchial body of the 4th Ph pouch (migrate into thryoid gland)
They produce calcitonin
Where may ectopic thyroid tissue be located?
Anywhere along path of descent of thyroid gland from floor of pharynx to thryoid cartilage
What may a midline neck swelling close to the hyoid bone be?
A thyroglossal cyst (50% are close to hyoid bone)
What is the vertebral level of the thyroid gland?
C5
Why might a thyroidectomy result in a disturbance in calcium and/or phosphorus metabolism?
If the parathyroid glands which are located on the posterioir surface of the thyroid gland and control calcium and phoshorus metabolism are also removed
Met What are the symptoms of hypocalcaemia?
Parathesia, tetany, paralysis and convulsions (due to hyperexcitablity of neuromuscular junction)
What muscles are related to the thyroid cartilage?
Omohyoid, sternohyoid and thyrohyoid muscles
Why might an enlarged thyroid gland (goitre) cause the voice to become hoarse?
If it compresses the recurrent laryngeal nerve
Describe the blood supply to the thyroid gland
Superior thyroid artery, the first branch of the external carotid, supplies anterosuperior aspect
Inferior thyroid artery, from the thryocervical trunk which is a branch of the subclavian, supplies posterior aspect
Describe the venous drainage of the thyroid gland
Superior, middle and inferior thyroid veins form thyroid plexus located on anterior surface if the gland
Which lymph nodes receive drainage from the thyroid gland?
Prelaryngeal, pre-tracheal and paratracheal which drain to the deep cervical lymph nodes
How is secretion by the thyroid gland controlled? (Met)
TSH secretion which is controlled by Hypothalamus-Pituitary-Thryoid axis
Name the parts of the pharynx and their borders
-base of skull-
Nasopharynx - chonane anteriroly, pharyngeal tonsil & C1 posteriorly
- soft palate-
Oropharynx - oral cavity anteriorly, C2&3 posteriorly
-epiglottis-
Laryngopharynx - larynx anteriorly, C3-6 posteriorly
What are the contents of the nasopharynx?
Nasopharyngeal tonsil (adenoids) Eustachian tube orifice
What are the contents of the oropharynx?
Pharyngeal tonsils
Anterior and posterior tonsillar pillars (palatoglossal and palatopharyngeal arches)
Describe the nature of the epithelium of the pharynx
Nasopharynx - respiratory - pseudostratified cilated columnar epithelium with goblet cells
Rest - stratified squamous non-keratinised
*What is the lymphatic drainage of the palatine tonsil?
Jugulo-digastric node (at angle of mandible)
*Describe Waldeyers ring
Ring of 4 aggregated sets of MALT that act as a barrier to infection: pharyngeal tonsil, tubal tonsils, palatine tonsils, lingual tonsils
Describe the musculature of the pharynx
3 circular layers that overlap each other - the superior, middle and inferior constrictors. Inferior has 2 components - thyropharyngeus and cricopharyngeus
3 longitudinal muscles - stylopharyngeus, paltopharyngeus and salpingopharyngeus
Describe the process of swallowing
Voluntary oral phase -> rapid non-voluntary pharyngeal phase in which tongue and suprahyoid muscles pull hyoid and larynx up, soft palate elevates to close off nasopahrynx and sup. constrictors contract -> food bolus pushed into hypopharynx by middle and inferior constrictors
How is the larynx protected during swallowing?
By overhanging tongue, epiglottis and vocal cords
What is the action of the longitudinal muscles of the pharynx?
Shorten and widen pharynx
Elevate larynx
Describe the motor innervation of the pharynx
Vagus
Glossopharyngeal nerve - stylopharyngeus
Which nerves provide sensory innervation to the pharynx?
CNV2 - nasopharynx
CNIX (glossopharyngeal) - oropharynx
CNXII (hypoglossal) - hypopharynx
Describe the blood supply of the pharynx
Sup. thyroid artery
Ascending pharyngeal artery
Ascending and descending palatine arteries
branches of Lingual, Facial and Maxillary arteries
Describe the venous drainage of the pharynx
Pharyngeal venous plexus from internal jugular vein
Why might the adenoid (pharyngeal) tonsils be enlarged?
Infection - viral or bacterial
What are the potential consequences of enlargement of the adenoid (pharyngeal) tonsils?
Eustachian tube obstruction -> recurrent or chronic otitis media
Nasal obstruction -> mouth breathing, feeding difficulty, snoring or obstructive sleep apnoea
What are the potential complications of an adenoidectomy?
Bleeding
Dislocation of atlanto-occipital joint from infection
Eustachian tube stenosis
Describe the epidemiology of nasopharyngeal carcinoma and name the most common type
Extremely rare in UK, more common in Chinese population
Squamous cell carcinoma most common type
What are the indications for tonsillectomy?
Recurrent tonsilitis
Previous peritonsillar abscess
Suspected cancer
Obstructive sleep apnoea
Describe how a pharyngeal pouch can form
Posterior herniation of pharyngeal mucosa in Killian’s area - between inferior constrictor and cricopharyngeal muscles due to weakness in this area, incoordination of pharyngeal phase of swallowing or cricopharyngeal spasm
Describe how a patient with a pharyngeal pouch may present (include epidemiology)
Dysphagia, hallitosis, regurgitation, aspiration, chronic cough, wieght loss
Typically over 70 and male
Describe the presentation of acute epiglottitis
Septic / Pyrexial >38’c
Leaning forward in classical tripod position with hands on knees
Drooling
Usually children
Describe the aetiology of acute epiglottitis
Bacterial infection - usually H. Influenzae type B, Staphylococci,
B. Haemolytic strep,
Pneumococci
How would you manage acute epiglottitis?
Don't attempt to examine! Secure the airway Broad spectrum antibiotics - ceftriaxone Steroids Throat swab and bloods
Describe the aetiology of laryngotracheobronchitis (croup)
Viral infection - Parainfluenza or influenza
Describe the presentation of laryngotracheobronchitis (croup)
Stridor
Harsh, subglottic “barking” cough
How should you manage a patient with laryngotracheobronchitis (croup)?
If mild - at home with oral antibiotics and steam inhalation
If mod/severe - inpatient -> IV antibiotics, humidifed O2, dexamethasone, nebulised adrenaline, if worsening intubate
What are the symptoms of foreign body airway obstruction?
Choking, coughing, disappearance of toy / after playing with foreign body
How serious is a foreign body airway obstruction?
Leading cause of death in 1-3 year olds!
What signs may you seen on radiology in a patient with a foreign body airway obstruction?
Opaque foreign body
Segmental or lobar collapse
Localised emphysema (from ball valve effect)
Air trapping
Name the parts of the larynx
Supraglottis Glottis Subglottis Piriform fossa Epiglottis Thyroid cartilage Cricoid cartilage Arytenoid cartilages Vocal cords
If food is stuck in the larynx where is it likely to be?
The piriform fossa - pear shaped depressed either side of laryngeal inlet
What is the epiglottis?
Leaf shaped plate of elastic fibrocartilage that is depressed during swallowing to cover larynx
Describe the various cartilages of the larynx
Thyroid cartilage with superior horns that articulate with hyoid bone and inferior horns that articulate with cricoid cartilage. This is a signet ring shape with 2 articular facets on each side.
Arytenoid cartilages are pyramid shaped and are located on top of the cricoid cartilage. They are involved in vocal cord movement.
Also - epiglottis
Describe the contents of the glottis
Vocal cords- have 4 layers: stratified squamous epithelium, Reinkes space, vocal ligament and vocalis muscle
Name the principle muscles of the vocal cords and state which is responsible for abduction and which is responsible for adduction
Posterior cricoarytenoid - ABduction
Lateral cricoarytenoid - ADduction
Which nerves provide motor innervation to the larynx?
Recurrent Laryngeal nerve - all muscles except..
Cricothyroid supplied by External Superior Laryngeal nerve
Describe the laryngeal blood supply and venous drainage
Superior and inferior laryngeal arteries - branches of sup. and inf. thyroid arteries
Superior and inferior laryngeal veins
List 6 causes of recurrent laryngeal nerve palsy, excl. idiopathic, thyroid disease and trauma
Laryngeal cancer Cervical lymphadeopathy Oesophageal cancer Apical lung cancer Aortic aneurysm Neuropathic - diabetes
Describe the epidemiology of laryngeal carcinoma
Rare but commonest head and neck cancer in the west
More common in males
List 3 causes of laryngeal carcinoma
Smoking, alcohol and HPV
Is hypopharyngeal cancer common?
No
What cell type is typically affected in carcinomas of the larynx?
95% of cases are squamous cell carcinoma
What is laryngeal crepitus and what is the clinical relevance of it?
Grating feeling when larynx is moved side to side by examiner
Its absence is a sign of laryngeal carcinoma or laryngeal trauma
What features in a history may lead you to suspect laryngeal cancer?
Foreign body sensation in throat Dysphagia Odynohagia (painful swallowing) Otalgia (ear ache) Hoarse voice Coughing Weight Loss Smoking history
What examinations and investigations may you perform in suspected laryngeal cancer?
Examine larynx for laryngeal crepitus Examine cervical lymph nodes Fibroptic endoscopy Barium swallow CT or MRI Direct pharyngo-laryno-oesophagoscopy and biopsy
2017 Why does a subdural haematoma tend to progress slower than an extradural one?
Subdural tends to be venous bleed while extradural tends to be arterial
2017 Explain the appearance of a sub arachnoid haemorrhage on CT scan.
Opacities extending down into sulci as blood collects between arachnoid and pia mater, the latter if which is closely related to the surface of the brain, (including down into its sulci.)
2017 Briefly describe how you can differentiate an extradural-from subdural- haemorrhage on CT
Extra dural - lens shaped / biconcave / lemon shaped
Epidural - crescent / banana shaped
2017 What risk do the falx cerebri and tentorium cerebelli pose in raised intracranial pressure?
Brain can be displaced and compressed against them
2017 Through which foramina do each of the cranial nerves exit the skull?
CN I - holes of cribriform plate CNII - optic canal CNIII, IV and Va - superior orbital fissure CNVb - foramen rotundum CNVc - foramen ovale CNVII and VIII - internal acoustic CNX and XI - jugular foramen Cranial roots of CNXI - foramen magnum CNXII - hypoglossal canal
2017 Where does the middle meningeal artery enter the cranial cavity?
Through the foramen spinosum in the base of the skull
2017 Name the most prolific type of immune cells in the brain
Microglia
2017 Describe the parts of the brainstem and (briefly) their functions
Midbrain - eye movements and reflex responses to sound and vision
Pons - sleeping, feeding
medulla - CVS and respiratory control
2017 Wheres the central sulcus of the brain?
Between the frontal and parietal lobes, on dorsal surface of brain
2017 What are the main functions of the cerbellum?
Co-ordination and motor learning
2017 Which lobe of the brain deals with vision?
Occipital
2017 What does the corpus callosum of the brain do?
Connects the 2 cerbreal hemispheres
2017 What is the uncus and what is its clinical relevance?
Central parts of the temporal lobes which can herniate and compress the midbrain if there is an increased intracranial pressure
2017 What is the hypothesised reason behind the strength of the connection between scents and/or sounds and memories?
All processed within the temporal lobe of the brain
2017 Why might frontal lobe damage cause impaired impulse control?
Frontal lobe is responsible for higher cognition
2017 What is the role of the thalamus?
Sensory relay station projecting to sensory cortex
2017 Which nerves pass through the cavernous sinus?
Occulomotor II, Trochelar IV,
Abducens VI,
Opthalmic and Maxillary branches of trigeminal VaVb
2017 Explain, with reference to the specific anatomy, how atherosclerosis in the carotid artery could lead to monocular blindness.
Thrombus could embolise and travel up internal carotid and ophthalmic arteries to occlude the central retinal artery.
2017 List 6 signs of cerebellar dysfunction
D - dysdiadochokinesia and dysmetria A - Ataxia N - Nystagmus I - Intention tremor S - Slurred speech / scanning dysarthria H - Hypotonia / heel-shin test positivity
