The fluid present between bony labyrinth and membranous labyrinth is

Options

A. endolymph
B. perilymph
C. lymph
D. serum

Answer

**Step-by-Step Solution:**

1. **Identify the Structures**: Understand the anatomy of the inner ear, which consists of two main parts: the bony labyrinth and the membranous labyrinth. The bony labyrinth is the outer structure, while the membranous labyrinth is contained within it.

2. **Define the Fluids**: Recognize that there are specific fluids associated with these labyrinths:
- **Endolymph**: This fluid is found within the membranous labyrinth.
- **Perilymph**: This fluid is located between the bony labyrinth and the membranous labyrinth.

3. **Analyze the Question**: The question asks for the fluid that is present specifically between the bony labyrinth and the membranous labyrinth.

4. **Select the Correct Fluid**: Since the fluid between the bony labyrinth and the membranous labyrinth is defined as perilymph, we can conclude that this is the correct answer.

5. **Eliminate Incorrect Options**:
- **Endolymph** is not the correct answer as it is contained within the membranous labyrinth.
- **Serum** is a blood fluid and irrelevant to the anatomy of the ear.
- **Lymph** refers to a fluid involved in the immune system and is not specific to the ear's anatomy.

6. **Final Answer**: Therefore, the fluid present between the bony labyrinth and the membranous labyrinth is **perilymph**.

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