Coiled prtion of membranous labyrinth is filled with

Answer

**Step-by-Step Solution:**

1. **Understanding the Membranous Labyrinth**: The membranous labyrinth is a system of interconnected ducts and chambers located within the inner ear. It is essential for the functions of hearing and balance.

2. **Components of the Membranous Labyrinth**: The membranous labyrinth consists of several parts, including the cochlear duct (responsible for hearing) and three semicircular canals (responsible for balance and equilibrium).

3. **Fluid Composition**: The membranous labyrinth is filled with a specific type of fluid. This fluid is crucial for the proper functioning of the sensory receptors located within the labyrinth.

4. **Identifying the Fluid**: The fluid that fills the membranous labyrinth is known as endolymph. It is distinct from another fluid called perilymph, which surrounds the membranous labyrinth.

5. **Conclusion**: Therefore, the coiled portion of the membranous labyrinth, specifically the cochlear duct, is filled with endolymph.

**Final Answer**: The coiled portion of the membranous labyrinth is filled with endolymph.

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