EN1.1-2 | ENT Foundations — Graded Quiz

Correct. The tympanic membrane is divided into the pars tensa (large, taut, three-layered) and the pars flaccida (Shrapnell's membrane — small, lax, superior to the anterior and posterior malleolar folds, with only two layers — outer squamous and inner mucosal, without the fibrous middle layer). The pars flaccida is where attic perforations (in unsafe CSOM/cholesteatoma) typically begin.

Tympanic membrane: two parts — pars tensa (large, taut, three-layered: outer squamous + middle fibrous + inner mucosal) and pars flaccida/Shrapnell's membrane (small, lax, no middle fibrous layer, sits superior to the malleolar folds). The umbo is at the tip of the malleus handle — the most concave point, at the centre-inferior area.

The pars flaccida is the superior lax portion — not inferior. The tympanic membrane is three-layered in the pars tensa. The umbo is at the centre-inferior area (tip of the malleus handle), not the most superior point.

Correct. The nasal turbinates are scroll-like bony structures covered by richly vascular and secretory nasal mucosa. Their primary function is to dramatically increase the surface area of the nasal cavity, creating turbulent airflow that maximises contact between inspired air and the warm, moist mucosa — heating, humidifying, and filtering the air before it reaches the lower respiratory tract.

Three nasal turbinates (inferior, middle, superior — and occasionally a supreme) increase the mucosal surface area dramatically, creating turbulent airflow that allows warming, humidification, and filtration (via the mucociliary escalator) of inspired air. The inferior turbinate is the largest and most clinically significant (target of rhinitis/decongestants).

The nasal septum provides structural division of the nasal cavity — the turbinates are not structural supports for the septum. Olfaction occurs at the olfactory neuroepithelium in the roof of the nasal cavity (not at the turbinates). Turbinates deliberately create turbulence — not laminar flow — to maximise air-mucosa contact.

Correct. The 'unsafe' type of CSOM is the atticoantral (squamosal) type. It is defined by an attic or marginal perforation through which stratified squamous epithelium migrates into the middle ear and mastoid, forming a cholesteatoma. Cholesteatoma erodes bone, risking intracranial complications (meningitis, brain abscess, lateral sinus thrombosis) and facial nerve injury — hence 'unsafe'.

CSOM safe = tubotympanic (mucosal) = central perforation, no cholesteatoma. CSOM unsafe = atticoantral (squamosal) = attic/marginal perforation + cholesteatoma. This is the most clinically important ENT classification — the unsafe type mandates mastoidectomy due to intracranial complication risk.

The tubotympanic (mucosal) type IS the safe type — it has a central perforation and no cholesteatoma. The unsafe type is atticoantral with cholesteatoma. Never conflate the perforation type or cholesteatoma status between the two.

Correct. Little's area, also called Kiesselbach's plexus, on the anteroinferior nasal septum is the commonest site of anterior epistaxis. It receives a rich anastomotic supply from four arteries (sphenopalatine, greater palatine, anterior ethmoidal, and superior labial), making it highly vascular and prone to bleeding — especially in children. Direct pressure or chemical/electrical cautery is effective.

Anterior epistaxis (70-90% of nosebleeds): Little's area = Kiesselbach's plexus on the anteroinferior nasal septum (common in children). Posterior epistaxis: sphenopalatine/Woodruff's plexus (elderly, hypertensives). This distinction guides management: anterior = direct pressure/cautery; posterior = posterior pack/intervention.

Woodruff's nasopharyngeal plexus and the sphenopalatine artery are sites of posterior epistaxis — which is less common but more severe, occurring in elderly or hypertensive patients. The inferior turbinate lateral wall is not a classical epistaxis site.

Correct. Ethmoidal nasal polyps are bilateral, multiple, arise from eosinophilic/allergic inflammation of the ethmoid mucosa, and are part of chronic rhinosinusitis with nasal polyps (CRSwNP) — typically in adults. Antrochoanal polyp (Killian's polyp) is characteristically unilateral and single, arising from the maxillary antrum, passing through the accessory ostium to fill the posterior choana and nasopharynx — most common in children and young adults.

Ethmoidal polyps: bilateral, multiple, allergic/eosinophilic aetiology (CRSwNP), pale and oedematous, from the ethmoid mucosa — adults. Antrochoanal polyp (Killian's polyp): UNILATERAL, SINGLE, from maxillary antrum through the accessory ostium → posterior choana → nasopharynx. Commonest in children and young adults. This laterality difference is a key EN known-trap.

Never swap the laterality: ethmoidal polyps are bilateral; antrochoanal polyp is unilateral from the maxillary antrum. Both types are not from the ethmoid. Antrochoanal polyps are more common in children/young adults — not adults over 40 (that demographic describes CRSwNP/ethmoidal polyps more).

Correct. Sound vibrations travel from the tympanic membrane to the malleus (handle attached to the TM) → incus (long process articulates with malleus head) → stapes (footplate fits into the oval window). The 22:1 lever-ratio transformation amplifies sound pressure approximately 25-30 dB for effective inner ear stimulation.

Ossicular chain: malleus (attached to tympanic membrane via handle) → incus (connects malleus to stapes) → stapes (footplate inserts into oval window of inner ear). The chain acts as a transformer, converting low-force large-displacement tympanic membrane vibration to high-pressure small-displacement oval window movement.

Sound transmission always proceeds tympanic membrane → malleus → incus → stapes → oval window → inner ear. Any reversal or transposition of the ossicles represents an error in fundamental middle ear anatomy.

Correct. Cricothyroidotomy is performed through the cricothyroid membrane in a 'cannot intubate, cannot oxygenate' emergency. The cricothyroid membrane is the most rapidly accessible part of the airway (palpable midline, relatively avascular), making it the preferred emergency approach. A formal tracheostomy (between the 2nd and 3rd tracheal rings) is the elective/planned procedure for longer-term airway management.

Cricothyroidotomy: through the cricothyroid membrane — EMERGENCY airway access. Tracheostomy: between 2nd-3rd tracheal rings — ELECTIVE/planned airway. The key: emergency = cricothyroid membrane (fastest, most accessible); elective = trachea below cricoid. Never conflate the two procedures or their anatomical sites.

The 2nd-3rd tracheal ring level is the site for tracheostomy (elective). Cricothyroidotomy through the cricothyroid membrane is the EMERGENCY procedure — not the other way around. The 1st-2nd tracheal ring level is not the conventional tracheostomy site in adults (risks subglottic stenosis).

Correct. Untreated or recurrent acute tonsillitis can result in peritonsillar abscess (quinsy — pus between the tonsil and its capsule, a common surgical emergency), deep neck space infections (parapharyngeal/retropharyngeal abscess), and obstructive sleep apnoea from tonsillar hypertrophy. Systemic complications include rheumatic fever and post-streptococcal glomerulonephritis after Group A streptococcal tonsillitis.

Complications of recurrent/inadequately treated adenotonsillitis: peritonsillar abscess (quinsy), parapharyngeal abscess, retropharyngeal abscess, obstructive sleep apnoea, cor pulmonale (in severe cases), rheumatic fever/glomerulonephritis (Group A streptococcal sequelae). These complications drive the indications for tonsillectomy.

Epistaxis from Kiesselbach's plexus is primarily associated with nasal/septal pathology, not tonsillitis. CSOM results from middle ear disease, often via Eustachian tube dysfunction from adenoid hypertrophy (not tonsillitis per se). Otosclerosis and Meniere's disease are distinct middle ear/inner ear disorders. JNA is a benign nasopharyngeal tumour of adolescent males — not a complication of tonsillitis.

Correct. Inner hair cells (IHC) are the primary sensory transducers of the cochlea. Although there are only about 3,500 IHCs compared to 12,000 outer hair cells, IHCs are connected to approximately 90-95% of afferent auditory nerve fibres. Deflection of their stereocilia by basilar membrane movement opens mechanosensitive ion channels, generating receptor potentials that drive cochlear nerve action potentials.

Organ of Corti: inner hair cells (IHC) = the primary sensory transducers (3,500 cells, 1 row, connected to ~90-95% of afferent cochlear nerve fibres). Outer hair cells (OHC) = amplification (electromotility via prestin). Pillar cells and Hensen's cells are supporting cells. Reissner's membrane separates scala vestibuli from scala media.

Pillar cells are structural supporting cells forming the tunnel of Corti. Hensen's cells are supporting cells at the outer edge of the organ of Corti. Reissner's membrane separates scala vestibuli from scala media and is involved in endolymph production regulation — not direct sound transduction.

Correct. This clinical picture is the classic presentation of Meniere's disease. The triad of episodic vertigo (lasting 20 minutes to several hours), fluctuating low-frequency sensorineural hearing loss, and tinnitus with aural fullness is caused by endolymphatic hydrops — abnormal accumulation of endolymph in the scala media. Recurrent episodes over months to years are typical. Management includes dietary salt restriction, diuretics, betahistine, and vestibular rehabilitation.

Meniere's disease: endolymphatic hydrops → classic triad of episodic vertigo (20 min–24 hours) + sensorineural hearing loss (low-frequency, fluctuating) + tinnitus (± aural fullness). BPPV = brief seconds-duration positional vertigo, normal hearing. Vestibular neuritis = single prolonged severe episode, no hearing loss. Acoustic neuroma = slowly progressive SNHL + unsteadiness, rarely episodic vertigo.

BPPV causes brief (<60 seconds) positional vertigo provoked by head movement, with no hearing loss and a positive Dix-Hallpike test. Vestibular neuritis causes a single severe episode of vertigo lasting days (no hearing loss). Acoustic neuroma presents with slowly progressive unilateral SNHL and unsteadiness — not typically episodic rotatory vertigo with aural symptoms.