Helicotrema connects

Options

A. Scala vestibuli and scala tympani filled with endolymph
B. Scala vestibuli and acala media filled with perilymph
C. Scala vestibuli and acala tympani filled with perilymph
D. Scala media and scala tympanil filled with endolymph

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure**: The helicotrema is a structure located at the apex of the cochlea in the inner ear. It is essentially a small opening or hole.

2. **Cochlea Composition**: The cochlea consists of three main chambers:
- **Scala Vestibuli**: The upper chamber filled with perilymph.
- **Scala Media (Cochlear Duct)**: The middle chamber filled with endolymph.
- **Scala Tympani**: The lower chamber also filled with perilymph.

3. **Function of the Helicotrema**: The helicotrema connects the scala vestibuli and scala tympani, allowing for the continuity of the perilymph fluid between these two chambers.

4. **Analyzing the Options**:
- **Option A**: Scala vestibuli and scala tympani filled with endolymph - **Incorrect** (both are filled with perilymph).
- **Option B**: Scala vestibuli and scala media filled with perilymph - **Incorrect** (scala media is filled with endolymph).
- **Option C**: Scala vestibuli and scala tympani filled with perilymph - **Correct** (both are indeed filled with perilymph).
- **Option D**: Scala media and scala tympani filled with endolymph - **Incorrect** (scala tympani is filled with perilymph).

5. **Conclusion**: The correct answer is **Option C**: Scala vestibuli and scala tympani filled with perilymph.

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