The perilymph of the scala tympani communicates with the cerebrospinal fluid of the subarachnoid space through which channel?

• A Vestibular aqueduct
• B Aqueduct of Fallopius (facial canal)
• C Helicotrema
• D Cochlear aqueduct ✓

Explanation

The cochlear aqueduct runs from the scala tympani near the round window niche through the temporal bone to open in the subarachnoid space of the posterior cranial fossa, allowing perilymph and CSF pressure equilibration. The vestibular aqueduct instead contains the endolymphatic duct and sac and links the vestibule to the posterior fossa dura, connecting endolymphatic rather than perilymphatic spaces. Helicotrema connects the two scalae to each other, not to CSF.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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