Scala typmpani is the part of

Options

A. Internal ear
B. Middle ear
C. Endolymphatic sac
D. Brain.

Answer

### Step-by-Step Solution:

1. **Identify Scala Tympani**: Scala tympani is also known as the tympanic duct. It is a specific structure within the ear.

2. **Location of Scala Tympani**: It is important to note that scala tympani is located in the inner ear. This distinguishes it from other parts of the ear such as the middle ear.

3. **Fluid Content**: Scala tympani is filled with a fluid called perilymph. This fluid plays a crucial role in the function of the inner ear.

4. **Function of Scala Tympani**: The primary function of scala tympani is to transduce the movement of air. This movement is initiated by the vibration of the tympanic membrane (eardrum) and the ossicles (small bones in the middle ear).

5. **Transmission of Vibrations**: The vibrations from the tympanic membrane and ossicles lead to the movement of fluid within the scala tympani. This movement ultimately stimulates the hair cells in the organ of Corti, generating nerve impulses.

6. **Evaluating Options**:
- Option A: Internal ear - Correct, as scala tympani is part of the inner ear.
- Option B: Middle ear - Incorrect, as scala tympani is not located here.
- Option C: Endolymphatic sac - Incorrect, as this is a different structure.
- Option D: Brain - Incorrect, as scala tympani is not part of the brain.

7. **Conclusion**: Based on the information discussed, the correct answer is that scala tympani is a part of the **internal ear**.