What is the function of the round window in the ear?
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It is involved in drug delivery and the placement of electrodes for cochlear implants.
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What is the function of the round window in the ear?
It is involved in drug delivery and the placement of electrodes for cochlear implants.
What is the Canal of Huguier associated with?
It is the exit of the chorda tympani.
Which pharyngeal arch gives rise to the tragus and anterior helix?
The 1st pharyngeal arch.
What is a Callaural fistula?
An external opening at the angle of the mandible with an internal opening at the floor of the EAC.
What is the narrowest part of the ear ossicles?
The long process of the incus.
What is the origin of the malleus and incus?
The 1st pharyngeal arch.
What is produced by the apocrine glands in the outer 1/3 of the EAC?
Wax.
What is the color of the tympanic membrane?
Pearly white/grey.
What is the angle of the tympanic membrane with the horizontal?
55°.
What is Scheibe dysplasia?
A cochleosaccular dysplasia, the most common anomaly of the inner ear.
Where is the cone of light located on the tympanic membrane?
Antero inferior quadrant.
What forms the tympanic plexus?
Jacobson’s Nerve, sympathetic plexus around the ICA, and the 9th cranial nerve.
What transmits sound vibrations to the scala vestibuli?
The foot process of the stapes at the oval window.
What is the largest ear ossicle?
Malleus.
What structures originate from the 2nd pharyngeal arch?
The rest of the pinna and the stapes suprastructure.
What is the management for a Callaural fistula?
Excision while taking care of the facial nerve.
At what age does the mastoid tip develop?
At 2 years.
What is the significance of the otic capsule?
It forms the bony labyrinth.
What is the most common cause of folliculitis in the EAC?
Staphylococcus.
What is the effective vibratory surface area of the tympanic membrane?
55 mm².
What is the common cause of diffuse otitis externa (swimmer's ear)?
Pseudomonas.
What does the umbo of the tympanic membrane attach to?
The tip of the malleus.
What is the management for a hematoma of the pinna?
Aspiration; for cauliflower ear, plastic surgery is indicated.
What is keratosis obturans?
Abnormal migration of skin in the EAC.
What is the management for keloids on the pinna?
Intralesional steroids or excision followed by postoperative intralesional steroids or radiation to prevent recurrence.
What type of joint is the incudomalleolar joint?
Saddle joint.
What is the origin of the tympanic membrane?
All three germ layers.
What is the narrowest part of the External Auditory Canal (EAC)?
Isthmus.
What can happen if a post auricular incision is made before 2 years of age?
It can injure the facial nerve at the stylomastoid foramen.
What is the ideal age for BAHA implantation?
At 5 years of age or with a skull thickness of 3 mm.
What are the two types of deficiencies in the floor of the EAC?
Fissure of Santorini (cartilaginous) and Fissure of Huskhe (bony).
What is Darwin's tubercle used for?
Identification.
What is the treatment for recurrent folliculitis in the EAC?
Investigate for diabetes mellitus (DM) and use topical antibiotics.
What is Mondini dysplasia?
A condition where only 1.5 turns of the cochlea are present, while normal is 2.75 turns.
What is the appearance of the ear in otomycosis?
Wet newspaper or cotton ball appearance.
How can you determine the side of the tympanic membrane?
By the handle of the malleus and the cone of light.
What is perichondritis and its common cause?
A condition characterized by a red, hot, painful pinna, commonly caused by Pseudomonas.
What is a keloid in relation to the pinna?
A firm, rubbery nodule on the pinna with a history of trauma.
What is a preauricular sinus?
A fusion defect of auricular tubercles, commonly found at the root of the helix.
What are microtia and anotia associated with?
Goldenhar syndrome and Treacher Collins syndrome.
What are the indications for hearing rehabilitation using BAHA?
Atresia, discharging ear, big ear cavity post-op, and single ear deafness.
What is the significance of the caloric test in ENT?
It stimulates the vestibular system and serves as a landmark for the facial nerve.
What is the smallest ear ossicle?
Stapes.
What type of joint is the incudostapedial joint?
Ball & Socket joint.
What is the significance of the persistent petrosquamous suture?
It can cause diseases in the antrum to be missed.
What is the composition of the outer 1/3 of the EAC?
Cartilaginous, approximately 8 mm long.
When does the Organ of Corti develop?
By 20-25 weeks of gestation.
What structures of the ear are not developed at birth?
Bony EAC and mastoid tip.
How many layers does the tympanic membrane have?
Three layers.
What is Lempert's incision?
An intercartilaginous incision site at the incisura terminalis.
Which part of the tympanic membrane is the most mobile?
Pars flaccida (Shrapnell's membrane).
What is Michel aplasia?
An absent labyrinth, which is a contraindication for cochlear transplant.
What is the main cause of Herpes Zoster Oticus?
Reactivation of Varicella Zoster Virus (VZV) in the geniculate ganglion.
What forms the promontory in the middle ear?
The basal turn of the cochlea.
What is the treatment for perichondritis?
Antibiotics, such as Ciprofloxacin.
What is the most common dehiscent segment of the facial nerve?
Tympanic/horizontal segment.
What causes accessory auricles or preauricular skin tags?
Abnormal fusion during ear development.
What is the recommended treatment for microtia/anotia?
Otoplasty or pinnaplasty using autologous rib cartilage after 6 years of age.
What is a hematoma in the context of the pinna?
An organized hematoma, also known as cauliflower ear, presenting as swelling on the lateral side of the ear.
What is the treatment for malignant otitis externa?
Antibiotics and debridement.
What is the significance of the processus cochleariformis?
It is a landmark for the first genu of the facial nerve and geniculate ganglion.
What does the tensor tympani attach to?
The upper end of the malleus handle.
