The apex of the cochlea contains a structure that connects which two scalae?

The apex of the cochlea contains a structure that connects which two scalae?

• A. Scala media and scala tympani
• B. Scala vestibuli and scala tympani
• C. Scala vestibuli and scala media
• D. Endolymphatic duct and perilymphatic space

Answer: (B)

At the apex of the cochlea, the helicotrema forms a bridge between the scala vestibuli and scala tympani, allowing perilymph to flow between these two compartments. This connection lets low-frequency pressure waves continue through the cochlea without being reflected at the apex, aiding proper transmission of those sounds. The scala media sits between them and contains endolymph, so it is not directly connected to the other two; and the endolymphatic duct and perilymphatic space refer to different structures and do not link the two scalae. So, the apex connects scala vestibuli and scala tympani.

At the apex of the cochlea, the helicotrema forms a bridge between the scala vestibuli and scala tympani, allowing perilymph to flow between these two compartments. This connection lets low-frequency pressure waves continue through the cochlea without being reflected at the apex, aiding proper transmission of those sounds. The scala media sits between them and contains endolymph, so it is not directly connected to the other two; and the endolymphatic duct and perilymphatic space refer to different structures and do not link the two scalae. So, the apex connects scala vestibuli and scala tympani.