Ear, Nose and Throat Flashcards
What does the outer ear consist of?
- Auricle-> cartilage (helix, tragus, concha) + lobule to capture + direct sound
- External auditory canal-> concha to tympanic membrane, outer 1/3 cartilage + produces wax, inner 2/3 bone
What is cauliflower ear?
- Blood accumulates between cartilage and perichondrium
- Disrupts blood supply
- Avascular necrosis
What is the tympanic membrane?
- Boundary between external + middle ear
- Umbo meets lateral process of malleus bone
- Pars flaccida (weak) + pars tensa
- Light reflex-> at 5’oclock (right ear) or 7 oclock (left)
What does the middle ear consist of?
- 1 nerve-> facial (CNVII)
- 2 muscles-> tensor tympani + stapedius (restrict ossicle movement + protect from loud noise)
- 3 bones/ossicles-> malleus + incus + stapes (from tympanic membranes to oval window + pass vibrations to inner ear)
- Mastoid process
- Eustachian tube
What is the mastoid process?
- Area of temporal bone behind ear
- Air cells protect ear + equalise air pressure
What is the role of the Eustachian tube?
- Middle ear has no direct contact with the atmosphere
- Pressure differences between outer + middle ear
- ET-> opens + allow equalisation
What does the inner ear consist of?
- Vestibular-> 3 semi-circular canals, utricle + saccule, messages to CNVIII
- Cochlear-> oval window, scala media + tympani + vestibuli (transmit into signals via organ of Corti)
How do the semicircular canals work?
- Endolymph + sensory hair cells
- Detect direction + flow when move
- Sends messages to CNVIII
What are the functions of the nose?
- Ventilation
- Humidify air
- Smell via olfactory nerve
- Protect airway from pathogens-> mucous + hairs
- Drainage from sinuses + tear ducts
- Middle ear ventilation via Eustachian tube
What is the anatomy of the nose?
- Cartilage, septum + bone
- Cavity-> vestibule to nasopharynx with CNI on superior aspect
- Superior, middle + inferior turbinates-> on lateral walls to increase surface area + improve humidity
What is the arterial blood source of nose?
- Little’s area-> Keisselbach’s plexus, anterior, source of epistaxis
- Woodruff’s plexus-> cause posterior nose bleeds
Who is at risk of posterior nose bleeds?
Older, HTN, atherosclerosis
Where do anterior nose bleeds usually come from?
Little’s area-> Keisselbach’s plexus
Where do posterior nose bleeds come from?
Woodruff’s plexus
What is the anterior triangle of the neck?
- Mandible (superior)
- Midline of neck (medial)
- Sternocleidomastoid (lateral)
What structures are in the anterior triangle of the neck?
- Thyroid + parathyroid
- CNs IX, X and XII
- Carotid artery
- Internal jugular vein
- Salivary glands
What is the posterior triangle of the neck?
- Sternocleidomastoid (anterior)
- Clavicle (inferior)
- Trapezius (posterior)
What structures are in the posterior triangle of the neck?
- Subclavian artery and vein
- External jugular vein
- CN XI
- Brachial plexus
Where are branchial cysts usually located?
Anterior triangle of the neck
Where are cystic hygromas usually located?
Posterior triangle of the neck
What anatomical structures are in the throat?
Hard + soft palate, uvula, palatine tonsils, tongue
Where are salivary tumours usually located?
Parotid gland
What runs through the parotid gland?
CN VII (facial nerve)
What is Stensen’s duct and where can it be found?
- Where saliva secreted from the parotid gland
- Feel as bulge on cheek opposite the second molar
What gland produces the most saliva when not eating?
Submandibular gland
What salivary gland produces the most mucous secretions and why?
Sublingual-> allow smooth food passage down oesophagus
What pathology is common in the sublingual glands?
Mucoceles
Where is the lymphatic drainage (including nodes) of the head and neck?
- Submental
- Submandibular
- Tonsillar
- Parotid
- Preauricular
- Deep cervical
- Superior + posterior cervical
- Supraclavicular
- Post auricular
- Occipital
What is conductive hearing loss?
Sound not conducted at ear canal to inner ear-> due to external or middle ear problem
What can cause conductive hearing loss?
Fluid, foreign object, allergies, ruptured tympanic membrane, impacted earwax
What is sensorineural hearing loss?
Sound is received at the inner ear but sensory problem-> due to cochlear or CNVIII problem
What causes sensorineural hearing loss?
Age related, noise damage, drug side effects, auditory tumours, blast/explosions
What can caused mixed hearing loss?
Genetics, infection, head trauma
What Rinne’s and Weber’s test results do you get in normal hearing?
- Weber-> equal on both sides
- Rinne’s-> air conduction>bone (ie louder when next to ear)
What Rinne’s and Weber’s test results do you get in sensorineural loss?
- Rinne’s-> air>bone conduction
- Weber’s-> lateralise to unaffected ear
What Rinne’s and Weber’s test results do you get in conductive loss?
- Rinne’s-> bone conduction>air
- Weber’s-> lateralised to affected ear
What causes otitis externa?
- External canal’s protective mechanism disrupted + bacteria trapped
- EG due to water, humidity, cotton buds, hearing aids, immunocompromised
- Pseudomonas aeruginosa
What pathogens usually cause otitis externa?
Pseudomonas aeruginosa, staph aureus, candida
How does otitis externa present?
Otalgia, otorrhoea, swollen + red ear, itching, tender pinna
How is otitis externa managed?
- Topical antibiotics + steroids
- Aural toilet
- Microsuction
What is necrotising/malignant otitis externa?
- Infection spreads to mastoid and temporal bones-> skull base osteomyelitis
- Can cause CN palsies and death if untreated
How is necrotising/malignant otitis externa managed?
Prolonged antibiotics
What is the pathophysiology of acute otitis media?
- URTIs migrate to eustachian tube into middle ear
- Kids-> shorter tube + easier transmission
- Viral-> RSV, rhinovirus, enterovirus
- Bacterial-> s.pneumoniae
What pathogens cause acute otitis media?
- Viral-> RSV, rhinovirus, enterovirus
- Bacterial-> s.pneumoniae
How does acute otitis media present?
Otalgia, inflamed tympanic membrane, malaise
How is acute otitis media managed?
- Self resolving with analgesia
- Amoxicillin if unwell
- Grommets-> in recurrent
What are the complications of acute otitis media?
- Perforated tympanic membrane-> discharge + sudden pain relief
- Hearing loss
- Mastoiditis
- CNVII palsy
- Intracranial infection
What is otitis media with effusion?
- Glue ear
- Non infective fluid in middle ear
What causes otitis media with effusion?
- Eustachian tube dysfunction-> wider + shorter in kids
- Congenital structural malformations eg cleft palate
- Allergies
- Adults-> consider malignant (obstruction of tube)
What are the symptoms and signs of otitis media with effusion?
- Hearing loss, speech delay in kids
- Exam-> dull tympanic membrane, upward reflecting/absent light reflex
How is otitis media with effusion managed?
- 50% resolve in 3 months
- Hearing aids
- Grommets
What is the pathophysiology of chronic otitis media?
- Tympanic membrane perforations after recurrent OM
- Non infective-> trauma or iatrogenic (eg grommets)