Which of the following membranes of cochlea divides the bony labyrinth into scala vestibuli and scala tympani ?

Options

A. Basilar and tectorial membrane
B. Basilar and tympanic membrane
C. Reissner's and basilar membrane
D. Reissner's and tectorial membrane

Answer

To solve the question regarding which membranes of the cochlea divide the bony labyrinth into scala vestibuli and scala tympani, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of the Cochlea**:
- The cochlea is a spiral-shaped structure in the inner ear that plays a crucial role in hearing. It consists of two main parts: the bony labyrinth and the membranous labyrinth.

2. **Identifying the Components**:
- The bony labyrinth contains three fluid-filled chambers:
- **Scala Vestibuli**: The upper chamber filled with perilymph.
- **Scala Media**: The middle chamber, also known as the cochlear duct, filled with endolymph.
- **Scala Tympani**: The lower chamber filled with perilymph.

3. **Membranes in the Cochlea**:
- The cochlea has two important membranes:
- **Basilar Membrane**: This membrane runs along the length of the cochlea and supports the organ of Corti, which contains hair cells that act as auditory receptors.
- **Reissner's Membrane**: This membrane separates the scala vestibuli from the scala media.

4. **Identifying the Correct Answer**:
- The question asks which membranes divide the bony labyrinth into scala vestibuli and scala tympani. The correct answer is:
- **Reissner's Membrane and Basilar Membrane**.
- Reissner's membrane separates the scala vestibuli from the scala media, while the basilar membrane separates the scala media from the scala tympani.

5. **Conclusion**:
- Therefore, the membranes that divide the bony labyrinth into scala vestibuli and scala tympani are **Reissner's Membrane and Basilar Membrane**.

### Final Answer:
**Reissner's Membrane and Basilar Membrane**

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