ENT Flashcards
What kind of receptor are taste/smell receptors?
Chemoreceptors
Where are taste receptors located?
Tongue, palate, epiglottis and pharynx
What is the lifespan of a receptor cell?
approx. 10 days
What are the four types of papilla on the tongue?
Filiform, fungiform, vallate and foliate
Which type of papilla does not contain tastebuds?
Filiform
What are “tastants”?
Taste provoking chemicals
What happens when tastants bind to taste buds?
Ionic channels change to produce a depolarising receptor potential which initiates APs in afferent nerves
Signals conveyed to brainstem and thalamus then to cortical gustatory areas in the frontal lobe
What nerve gives supply to the epiglottis and pharynx?
CNX, vagus
What are the five primary tastes?
Salty, sour, sweet, bitter, umami
What stimulates salty taste receptors?
Chemical salts, especially NaCl
What stimulates sour taste receptors?
Acids with free H+ ions
What stimulates sweet taste receptors?
Glucose
What stimulates bitter taste buds?
Alkaloids, poison and toxic plant derivatives
What stimulates umami taste buds?
Amino acids, especially glutamate
What is ageusia?
Loss of taste
What is hypoguesia?
Reduced taste function
What is dysguesia?
Distortion of taste
What can cause aguesia?
Nerve damage, inflammation, endocrine disorders
What can cause hypogeusia?
Medication or chemo
What can cause dysguesia? (9)
Glossitis, gum infection, tooth decay, reflux, URTIs, medication, cancer, zinc, chemo
Which cell types does olfactory mucosa contain?
Olfactory mucosa, supporting cells and basal cells
Describe the structure of an olfactory receptor.
Thick short dendrite with a wide end called an olfactory bulb from which there is cilia projections
What is the lifespan of an olfactory receptor?
2 months
Describe the path of a signal from the olfactory nerve to the brain.
Olfactory receptors which then form afferent fibres of the olfactory nerve which pierces the cribiform plate to enter olfactory bulbs in the inferior surface of the brain then along the olfactory tract to reach the temporal lobe and olfactory areas.
How do odorants reach receptors in quiet breathing?
Diffusion
What must a substance be in order to be smelled?
Volatile to be inspired with air
Soluble in water to dissolve in the mucous
What is anosmia?
Inability to smell
What can cause anosmia?
Viral infection, allergy, nasal polyps, head injury
What is hyposmia?
Reduced ability to smell
What is dysosmia?
Altered sense of smell
At which frequencies do humans perceive sound?
20-20,000Hz
Summarise the main role of the outer ear
Sound collector
Summarise the main role of the middle ear
Mechanical force amplifier
Summarise the main role of the inner ear
Sound transducer
What is the TM to OW ratio?
18:1
Where are sound waves transmitted to after the OW?
Cochlea, organ of Corti on basilar membrane
Which nerve is stimulated on depolarisation of the Organ of Corti?
CN VII, vestibulocochlear (then to central pathways)
In the rest state is the Eustachian tube opened or closed?
Closed
Which muscles can open the Eustachian tube?
Tensor veli palatine and levator palatine
Why does the Eustachian tube open?
To equalise pressure in the ear
What is the scala media?
Cavity inside cochlea, between the tympanic duct and the vestibular duct, separated by the basilar membrane and Reissner’s membrane
What does the scala media contain?
Endolymph and Organ of Corti
What do the scala tympani and the scala vestibule contain?
Perilymph
When do the hair cells on the cochlea depolarise?
When hairs are deflected towards the longest hair
What are the five vestibular end organs?
Ampullae of lateral, posterior and superior semi-circular canals
Maculae of utricle and saccule
What process does the brain perceive as movement?
Weight of the gelatinous matrix changing
This is where the stereocilia/hairs of the utricle and sacuule project
What are otoconia?
Calcium carbonate crystals
Where at otoconia found?
Utricle and saccule
What do otoconia do?
Sense linear movement and gravitational movement
What happens to otoconia on movement?
They exert a shearing force on the hair they are coupled to
How are signals transmitted from the utricle and saccule?
Utricle - superior division of vestibular nerve
Saccule - inferior division of the vestibular nerve
Why are throat swabs not routinely carried out?
Due to commensals which are not the causative organism
When would you considering referring sore throat?
If neck mass present or if lasts longer than 3-4 weeks
When would you considering referring dysphagia or odynophagia?
If progressive or lasting >3 weeks
What supportive advice would you give a sore throat?
Avoid hot drinks, good fluid intake, warm salty water washes
What are the points on the Centor criteria?
Tonsillar exudate; cervical lymphadenopathy; fever; no cough
Who can’t the Centor criteria be used for?
Children under 3
What is the most common bacterial cause of sore throat?
Strep pyogenes
What is strep pyogenes?
Gram positive cocci, beta haemolytic
Which conditions may occur following a sore throat?
Rhuematic fever 3 weeks post sore throat
Glomerulonephritis 1-3 weeks post sore throat
How does diphtheria present?
Severe sore throat with a white membrane across the pharynx
Which bacteria causes diphtheria?
Corynebacterium diptheriae
When is the toxoid vaccine for diphtheria given?
2, 3 and 4 months
How is diphtheria treated?
Anti-toxin, penicillin/erythromycin and supportive treatment
What causes oral thrush?
Candida albicans
How does oral thrush present?
Patches of red raw mucous membranes in the throat and mouth
How is oral thrush treated?
Nystatin
Which group most commonly gets acute otitis media?
Children and infants
How does acute otitis media present?
Discharge, hearing loss, fever, lethargy
Which bacteria commonly cause acute otitis media?
H influenzae
Strep pyogenes
When do you take a swab in acute otitis media?
If the TM perforates, but not unless that happens
How should acute otitis media be treated?
Most resolve within 4 days without abx
If not, give amoxicillin or erythromycin
If immunocompromised, systemic illness or bilateral AND under two, give abx immediately
How does acute sinusitis present if there is secondary bacterial infection?
Severe pain and tenderness with purulent nasal discharge
What usually predisposes acute sinusitis?
URTI
How is acute sinusitis treated?
If severe/deteriorating for >10 days, penicillin or doxycycline
Most are self limiting over 2.5 weeks
What is otitis externa?
Infection of the outer ear canal
How does otitis externa present?
Swelling and redness of the ear canal, itch, pain, discharge
What are bacterial causes of otitis externa?
Staph aureus, pseudomonas aeruginosa
What are fungal causes of otitis externa?
Aspergillus niger, candida albicans
How is bacterial otitis externa treated?
Topical aural toilet
How is fungal otitis externa treated?
Topical clotrimazole (canesten) or gentamicin 0.3% drops
What is malignant otitis externa?
Extension of otitis externa into the surrounding ear canal
Which bones does malignant otitis externa commonly affect?
Mastoid and temporal
How does malignant otitis externa present?
Disproportionately severe pain and headache; exposed bone in ear canal and facial nerve palsy
How is malignant otitis externa investigated?
PV, CRP, imaging, biopsy and culture
What is a culture in malignant otitis externa most likely to show?
Pseudomonas aerginuosa
Which patients are at risk of malignant otitis externa?
Immunocompromised and radiation to head and neck
Which virus causes infectious mononucelosis?
EBV
How does infectious mononucleosis present?
Fever, lymphadenopathy, sore throat, pharyngitis, tonsillitis, malaise, lethargy, jaundice, rash, atypical lymphocytes
How is infectious mononucleosis treated?
Usually self-limiting over 4 weeks, paracetamol
Corticosteroids if it is a complicated case
What advice should be given to infectious mononucleosis patients?
Avoid sport for 6 weeks (to avoid splenic rupture); get bed rest; avoid alcohol
How is infectious mononucleosis investigated?
EBV IgM; Paul Bunnell test; FBC; LFT; monospot film
When is HSV Type 1 most likely to be acquired?
In childhood, through saliva contact
What are the symptoms of HSV type 1?
May be asymptomatic OR systemic upset, fever, inflammation, vesicles on lips, buccal mucosa and hard palate
How is HSV type 1 treated?
Acyclovir 3 weeks
Which type of HSV tends to reactivate more?
HSV Type 2
Which virus causes genital herpes?
HSV Type 1 or 2
What is a herpetic whitlow?
Paiful lesion on finger or thumb caused by HSV
How is HSV confirmed?
Swab of whitlow lesion and PCR
What causes herpangina?
Coxsackie virus (enterovirus)
How does herpangina present?
Vesicles or ulcers on soft palate
How is herpangina diagnosed?
PCR test of swab in medium
What are apthous ulcers?
Recurring painful oval ulcers around the mouth which have inflammatory halos
How are apthous ulcers treated?
Self-limiting over 3 weeks
Which bacterium can cause syphilis?
Bacterium treponema pallidum
How is syphilis investigated?
IgG and IgM antibodies
How is syphilis treated?
IM Penicillin
What are important facts to find out on nasal trauma?
Blood/discharge, airway restriction, LOC
What is a septal haematoma?
“boggy” swelling in the nasal apertures
How is septal haematoma treated?
Incised and drained under LA
What is a complication of stagnant blood in the nose?
Infection, leading to abscess
From what does the cartilage of the nasal septum receive its blood supply?
Perichondrium
How are nasal fractures managed?
Diagnosed clinically, reviewed in 5-7 days when swelling goes down, can be straightened under LA within 2 weeks
Which arteries supply the nose?
Sphenopalatine, ethmoid and greater palatine
What can be given in epistaxis if bleeding does not cease within 10 mins?
Lignocaine and adrenaline, cauterisation with silver nitrate
What may fracture to cause a CSF leak?
Cribiform plate of the ethmoid bone
What is otherwise known as cauliflower ear?
Pinna haematoma
How is a pinna haematoma treated?
Drained and sutured together, pressure dressing applied
How is a laceration on the outer ear treated?
Sutured in the anatomical position (may need to remove some cartilage)
What shouldn’t be used in the ear for risk of necrosis?
Adrenaline
What are “racoon eyes” or bruising posterior to the ear indicative of?
Temporal bone fracture
What should be done in a temporal bone fracture?
Test hearing for TM function, CNVII testing
What is haemotympanum?
Blood behind the TM
What can cause haemotympanum or ossicular chain disruption?
Temporal fractures
What can haemotympanum or ossiculr chain disruption cause?
Conductive deafness
In how many patients does facial palsy accompany temporal fractures?
Longitudinal - 20% of cases
Transverse - 80% of cases
How do temporal fractures come about?
Transverse - frontal blows
Longitudinal - lateral blows
Which kind of temporal fracture is more common?
Longitudinal
Where are transverse temporal fractures seen?
Perpendicular to the long axis of the petrous pyramid
What is conductive hearing loss?
When sound isn’t properly conducted through the ear canal
What can cause conductive hearing loss?
Fluid in the ear canal, TM perforation, ossicular disruption, stapes fixation (osteosclerosis?)
What can cause sensorineural hearing loss?
CNVIII palsy, cochlea pathology
What is sensorineural hearing loss?
Problems which changing sound waves into electrical impulses (transduction)
How is facial paralysis managed?
Never decompression and EMG studies
In which group(s) is neck trauma more common?
Men (fight), adolescents (dumb)
What does Zone 1 of the neck include?
Trachea, oesophagus, thoracic duct, thyroid, vessels and spinal cord
What are the borders of zone 1 of the neck?
Clavicles to cricoid cartilage
What are the borders of zone 2 of the neck?
Cricoid cartilage to angle of mandible
What does Zone 2 of the neck include?
larynx, hypopharynx, CNX, XI, XII, carotids, internal jugular, spinal cord
What does Zone 3 of the neck include?
Pharynx, caortids, IJV, spinal cord
What are the borders of Zone 3 of the neck?
Angle of mandible to base of skull
What is a complete penetrating neck injury?
One which completely goes through the platysma
How should a neck injury be investigated?
Endoscopy, FBC, CXR, CT angiogram
When should urgent exploration be done in the neck?
If suspicion of expanding haematoma, hypovolaemic shock, airway obstruction of blood in aerodigestive tract.
What urgent investigation should be done?
Bronchoscopy, phayngoscopy, oesophagoscopy
What is the weakest point of the orbital rim?
Infraorbital groove
Where do most fractures of the bony oribt occur?
Posterior medial section (as is the thinnest)
What is a “tear drop sign” on CT?
Shows infraorbital contents coming into the sinus (due to a blow out fracture)
How are bony orbit fractures managed?
Conservatively
Surgical repair if there is entrapment, large defects or significant exophthalmos
Where is a Le Fort I fracture?
Across the apices of the theeth
Where is a Le Fort II fracture?
Through frontal maxilla, through lacrimal bone and inferior orbital floor
Which cartilage determines the diameter of the larynx?
Cricoid
What is the karina?
When the trachea splits into the left and right bronchus
What does Poiseuille’s equation show?
Larger radius of trachea = less resistance (therefore less work of breathing)
What are sternal or subcostal recession signs og?
Airway obstruction
How is epiglottitis treated?
Give antibiotics and fluids, get ENT consultant
How are foreign bodies investigated?
Bronchoscopy
What causes recurrent respiratory papillomatosis?
HPV 6, 11, 16, 18
How is a sub-glottis stenosis treated?
Cut in 4 places and inflate balloon to set size, then inject steroids
What can causes subglottic stenosis?
Vasculitis
What should be assessed in suspected airway obstruction?
Work of breathing, skin circulaions
When should tracheostomy be performed?
As a last resort
What simple test can be done first to check hearing?
Tuning fork test
What does a tympanogram show?
How the TM moves/how mobile it is
What may reduce a tympanogram?
Fluid or something else behind the TM
What are the 4 types of deafness?
Conductive, sensorineural, mixed, central
Where may referred pain in the ear be coming from?
Back of the throat (CN IX), always look in throat
How can a CSF leak present?
Clear discharge from the ear
What does dizziness suggest?
That the inner ear is damaged
If dizziness but no hearing loss, what could this be?
BPPV or vestibular neuronitis
What is tinnitus?
Constant extra sounds
Which age group typically gets AOM?
Children
How does AOM present?
Red, swollen, angry ear, tender
Bacterial infections will cause yellow/smelly discarhge
What is “glue ear”?
Otitis media with effusion.
Presence of fluid blocks Eustachian tube
How is “glue ear” treated?
Nothing for three months if unilateral
If >3 months or bilateral then offer heaing aid or grommet insertion
What is a cholesteatoma?
Skin in the wrong place (middle of ear) causing flaky discharge
What is vertigo?
The sensation of the room spinning
What do the lateral semi-circular canals do?
Sense rotational movement
What do the superior semi-circular canals do?
Sense vertical movement
What does the utricle sense?
The downward force of gravity
What is the vestibulo-ocular reflex?
When the head is turned to one side, there is increase firing in the semi-circ canals on that side, and reducedon the other
How do you determine if the cause is vestibular or not?
Videonystagmogrpahy
What can failure of the vestibule-ocular reflex cause?
Nystagmus
How should “dizziness” be investigated?
Otoscopy, neurologically, BP, balance, audiometry
How does BPPV present?
Vertigo on leaning forward or back or turning over in bed for 30s to 1min.
What causes BPPV?
Calcium carbonate on hair cells break free, float up in fluid and sit in the posterior semi-circular canal
What test should be done for BPPV? Describe it.
Hallpike’s test.
Position the patient sitting but so when the lie back their head will be over extended. Turn the head to one side and lie back in one quick motion. Nystagmus present on BPPV.
Which manoeuvre is done to attempt to move the otoliths back to the utricle in BPPV?
Epley manoeuvre
Sit, head to left, head to right, recovery position, sit.
How often should the Epley manoeuvre or Brandt-Daroff exercises be performed?
5 times in a set
3 sets per day
2 weeks
What is vestibular neuronitis?
Vertigo for up to 3 days
What may precede vestibular neuronitis?
Viral symptoms
How does labrynthitis present?
Sudden onset vertigo which improves over a few days with hearing loss or tinnitus
How is labyrinthitis treated?
Vestibular sedatives or prochloperazine/buccastem (dopamine receptor antagonist), but normally self-limiting
How is Meniere’s diagnosed?
Diagnosis of exclusion
What happens during an attack in Meniere’s?
Vertigo so violent it makes people sick and they are too dizzy to do anything during the attack
What may precede an attack in Meniere’s?
Worsening tinnitus and hearing loss
What dietary factors may help Meniere’s?
Salt restriction
What happens to the endolymphatic space in a Meniere’s attack?
There is a break which allows the two fluids to mix and damage organs
What should be done if hearing is completely lost?
Give gentamicin to destroy the balance function in the ear
can’t get an attack on ur balance if u don’t have balance
Which kinds of tissue does MRI visualise best?
Soft tissue
What is the common separate primary tumour for a head and neck cancer?
Lung
What is the most common type of tumour in the head and neck?
SCC
Which side of the vocal cords is more likely to be paralysed?
The left, due to its longer course
What may a high resp rate indicate with regards to a head and neck cancer?
Upper airway mass/narrowing
What is the 5 year survival rate of head and neck cancer?
25%
Why might plastic surgery be under taken?
Aesthetics, reconstruction, functional
What is the botulinum toxin and how does it work?
Botox
Paralyses small parts of the muscle for 3-6 months
What two naturally occurring options can be used as a filler?
Fat or hyaluronic acid
What must be done before wound closers?
Clean, debridement, checked for foreign bodies
What is primary wound closure?
When the wound edges are pulled together
What is rhinitis?
An infection or non-infective inflammation of the mucosal membrane of the nose
What can infective rhinitis progress to?
Rhinosinusitis
What can cause non-infective rhinosinusitis?
Allergy, vasomotor issues or polyps
What is intermittent allergic rhinitis set off by pollen better known as?
Hayfever
What may cause persistent rhinitis?
House dust mite allergy, pet saliva allergy
What can medication can be given for rhinitis?
Anti-histamines for immediate relief
Min dose topical steroids for background defence
Immunotherapy for IgE mediated reactions
How can polyps in the nose be treated?
Steroids, but more commonly surgically excisesd
How is infective rhinosinusitis treated?
Not treated unless worsening over 5 days or leads to orbital cellulitis
How does rhinosinusitis present?
Pain, discharge and blockage
Why does orbital cellulitis need treated in rhinosinusitis?
Risk of blindness and potential spread to brain
What tests should be performed in non-infective allergic rhinitis?
Skin prick testing, RAST for specific IgE
What might a painful, boggy swollen nose be indicative of?
Septal haematoma
What complication may occur in septal haematoma?
Cartilage necrosis and collapse
What to the palatine tonsils develop from?
Dorsal wing of the 1st pharyngeal pouch, ventral wing of second pouch
When do adenoid tonsils developed?
16 weeks gestation
What is the tonsillar fossa formed by?
Muscular tonsillar pillars - palatoglossus and palatopharyngeus
What are “crypts” on the tonsils?
Stratified squamous epithelium deeply invaginates the tonsil to form crypts
What is the epithelium in the adenoid tissue made of?
Ciliated pseudostratified columnar
What causes acute viral tonsillitis?
EBV, rhinovirus, parainfluenza, enterovirus and adenovirus
What causes acute bacterial tonsillitis?
GABHS - Strep pyogenes/pneumo, SA, H influenzae
How does viral acute tonsillitis present?
Malaise sore throat, fever, lymphadenopathy
How does bacterial acute tonsillitis present?
Odynophagia, halitosis, unable to do normal activity
What treatment is given with a Centor criteria score of 0-1?
No antibiotics
What treatment is given with a Centor criteria score of 2-3?
Delayed abx, chance of infection
What treatment is given with a Centor criteria score of >4?
Treated empirically with abx, probably bacterial infection
Which antibiotic is given in tonsillitis?
Penicillin 500mg QDS for 10 days
Clarithromycin if allergic
When is a tonsillectomy considered?
If >5 cases per year for 2 years
or
>7 prescriptions for one year
>3 per year for 3 years
How does a peritonsillar abscess form?
When bacterial escapes the capsule of the tonsil and produces pus
How does a peritonsillar abscess present?
Odynophagia and sore throat following tonsillitis, displacement of the uvula
How is a peritonsillar abscess treated?
Aspirin and abx, drain if they don’t “pop” themselves
What virus commonly causes glandular fever?
EBV
How does glandular fever present?
Membranous exudate, lymphadenopathy, petechial haemorrhages, hepatosplenomegaly
How is glandular fever investigated?
EBV IgM, monospot and Paul Bunnell tests
How is glandular fever treated?
Antibiotics and steroids for 6 weeks
How is obstructive hyperplasia in kids treated?
Usually isn’t as there is a good chance they will regress as child grows
What are risk factors for “glue ear”?
Kids, daycare, smokers in household, recurrent UTRI, immunodeficiency, bottle feeding, preterm
What will tuning fork tests show in glue ear?
Conductive hearing loss
What are complications of grommets?
Infection risk, early extrusion, perforation
