The perilymph in the scala vestibuli and scala tympani communicates through the helicotrema and ultimately drains via which structure?

• A Cochlear aqueduct into the subarachnoid space ✓
• B Endolymphatic duct via the cochlear aqueduct
• C Vestibular aqueduct into the posterior cranial fossa
• D Endolymphatic sac into the dural venous sinuses

Explanation

Perilymph communicates with the cerebrospinal fluid via the cochlear aqueduct (perilymphatic duct), which opens near the round window and leads to the subarachnoid space of the posterior cranial fossa. In contrast, endolymph drains into the endolymphatic sac (a blind-ended dural structure) via the endolymphatic duct through the vestibular aqueduct.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.