INI-CET 2017 - ENT PYQs Practice Questions

Q: Which of the following marked arrows represents the lateral semicircular canal during a cortical mastoidectomy?

C. **Correct Answer: C** - The **lateral semicircular canal** is typically identified by its superior and lateral position to the **facial nerve** and its prominence in the mastoid air cell system. - During a **cortical mastoidectomy**, it serves as a crucial anatomical landmark, especially when approaching the **aditus ad antrum** and planning for otologic surgery. *Incorrect Option A* - This arrow likely indicates the **tegmen tympani** (roof of the tympanic cavity), which is the superior boundary of the mastoid and middle ear, not a semicircular canal. - Damage to this area can lead to a **CSF leak** or **meningitis**. *Incorrect Option B* - This arrow points to the **facial nerve**, which runs inferior and medial to the lateral semicircular canal within the mastoid. - The facial nerve is extremely vulnerable during mastoidectomy and its identification is critical to prevent **facial paralysis**. *Incorrect Option D* - This arrow represents the **posterior semicircular canal**, which lies inferior and posterior to the lateral semicircular canal. - It is typically identified deeper within the mastoid and oriented more vertically compared to the lateral canal. [Practice more ENT PYQs on OnCourse]

Q: An intra-operative photograph of cortical mastoidectomy is shown. Identify the lateral semi-circular canal. (AIIMS Nov 2017)

D. ***Correct Option D*** - The diagram shows a simplified view of the temporal bone anatomy post-mastoidectomy, and 'D' clearly points to the position of the **lateral semicircular canal**. - During cortical mastoidectomy, the **lateral semicircular canal** is typically identified in the superior and posterior wall of the mastoid cavity, just above the aditus and facial nerve. - This is a critical landmark during mastoid surgery as injury to it can cause vertigo and hearing loss. *Incorrect Options A, B, and C* - These labels point to other anatomical structures visible in the mastoid cavity during cortical mastoidectomy, such as the tegmen tympani, facial nerve, sigmoid sinus, or other osseous landmarks. - Proper identification of the lateral semicircular canal is essential to avoid iatrogenic injury during surgery. [Practice more ENT PYQs on OnCourse]

Q: Which of the following is the diagnosis of the audiogram shown below?

Noise induced hearing loss. ***Noise induced hearing loss*** - The audiogram shows a classic **'noise notch'**, characterized by a dip in hearing at **3000-6000 Hz**, with recovery at 8000 Hz, reflecting damage to hair cells in the cochlea from excessive noise exposure. - Both air conduction (solid line) and bone conduction (dashed line) thresholds are depressed in the same pattern, indicating a **sensorineural hearing loss**. *Otosclerosis* - Otosclerosis typically causes a **conductive hearing loss**, meaning air conduction thresholds would be significantly worse than bone conduction thresholds, showing an **air-bone gap**. - It often results in a characteristic **Carhart notch** (a dip at 2000 Hz) in bone conduction, but this audiogram shows sensorineural loss without a significant air-bone gap. *Ototoxicity* - Ototoxicity usually results in a **high-frequency sensorineural hearing loss**, often affecting frequencies above 4000 Hz first, and typically shows a more gradual, sloping loss rather than a sharp notch. - While it is sensorineural, the specific 'notch' pattern seen here is more characteristic of noise exposure. *Meniere's disease* - Meniere's disease classically presents with a **low-frequency sensorineural hearing loss** that can fluctuate, accompanied by **tinnitus, vertigo, and aural fullness**. - The audiogram does not show a low-frequency loss, nor does it typically present with a noise notch. [Practice more ENT PYQs on OnCourse]

Q: The following image shows:

Respiratory papillomatosis. ***Respiratory papillomatosis*** - The image displays multiple **wart-like growths** on the vocal cords, characteristic of **respiratory papillomatosis**, which is caused by the **human papillomavirus (HPV)**. - These lesions often have an **irregular, cauliflower-like appearance** and can recur even after removal, making it a challenging condition to manage. *Vocal nodule* - Vocal nodules are typically **bilateral, symmetrical lesions** located at the junction of the anterior and middle thirds of the vocal cords. - They are usually **smooth, small, and whitish**, resulting from chronic vocal abuse, unlike the irregular and multiple growths seen in the image. *Vocal polyp* - Vocal polyps are typically **unilateral lesions** that can appear as sessile or pedunculated masses on a vocal cord. - They are often **larger than nodules** and may have a reddish or gelatinous appearance, but they usually occur singly, not as multiple diffuse growths like those pictured. *TB of vocal cords* - Tuberculosis of the vocal cords often presents with **ulcerative lesions**, granulomas, or diffuse inflammation, and may be accompanied by other signs of pulmonary TB. - The lesions caused by TB are generally **not papillomatous** or wart-like in nature, differentiating them from the appearance in the image. [Practice more ENT PYQs on OnCourse]

Q: Identify the line shown in the given image:

Donaldson line. ***Donaldson line*** - The image illustrates the posterior aspect of the petrous temporal bone, showing the relationship between the **facial nerve**, **posterior semicircular canal**, and the **endolymphatic sac**. - The dashed line directly passes superomedial to the **endolymphatic sac** and inferolateral to the **posterior semicircular canal**, which is characteristic of Donaldson's line, used as a surgical landmark. *Ohngren's line* - Ohngren's line is a radiological landmark used in the context of **maxillary sinus tumors**. - It runs from the **medial canthus of the eye** to the **angle of the mandible**, dividing the maxillary sinus. *Weber Ferguson line* - The Weber-Ferguson incision is a **facial incision** used for access to the **maxillary sinuses and midface**. - It is a surgical approach, not an anatomical line delineating internal structures. *Frankfurt line* - The Frankfurt horizontal plane, or Frankfurt line, is an **anthropometric landmark** used in craniometry and orthodontics. - It is defined by the superior border of the **external auditory meatus** and the inferior orbital rim. [Practice more ENT PYQs on OnCourse]

Question 1

Which of the following marked arrows represents the lateral semicircular canal during a cortical mastoidectomy?

Accepted Answer

C

Answer

A

Answer

B

Answer

D

Question 2

An intra-operative photograph of cortical mastoidectomy is shown. Identify the lateral semi-circular canal. (AIIMS Nov 2017)

Accepted Answer

D

Answer

A

Answer

B

Answer

C

Question 3

Which of the following is the diagnosis of the audiogram shown below?

Accepted Answer

Noise induced hearing loss

Answer

Otosclerosis

Answer

Ototoxicity

Answer

Meniere's disease

Question 4

The following image shows:

Accepted Answer

Respiratory papillomatosis

Answer

Vocal nodule

Answer

Vocal polyp

Answer

TB of vocal cords

Question 5

Identify the line shown in the given image:

Accepted Answer

Donaldson line

Answer

Ohngren's line

Answer

Weber Ferguson line

Answer

Frankfurt line

INI-CET 2017 — ENT