Which of the following part in ear is filled with endolymph ?

Options

A. Scala vestibuli
B. Scala tympani
C. Median canal
D. Helicotrema

Answer

To answer the question "Which of the following part in ear is filled with endolymph?", we will analyze each of the given options step by step.

### Step-by-Step Solution:

1. **Understanding the Structure of the Ear**:
The ear consists of several parts, including the cochlea, which has three main chambers: scala vestibuli, scala tympani, and scala media (or cochlear duct).

2. **Evaluating the Options**:
- **Option 1: Scala Vestibuli**:
- This is the upper chamber of the cochlea. It is filled with a fluid called perilymph, not endolymph.
- Therefore, this option is incorrect.

- **Option 2: Scala Tympani**:
- This is the lower chamber of the cochlea. Like the scala vestibuli, it is also filled with perilymph.
- Thus, this option is also incorrect.

- **Option 3: Median Canal (Scala Media)**:
- This is also known as the cochlear duct. It is the middle chamber of the cochlea and is filled with endolymph.
- The organ of Corti, which is responsible for hearing, is located here. Hence, this option is correct.

- **Option 4: Helicotrema**:
- This is a small opening at the apex of the cochlea that connects the scala vestibuli and scala tympani. It does not contain endolymph; instead, it allows the flow of perilymph between the upper and lower chambers.
- Therefore, this option is incorrect.

3. **Conclusion**:
Based on the analysis, the correct answer is **Median Canal (Scala Media)**, as it is the part of the ear that is filled with endolymph.