Which of the following statement is not correct regarding cochlea?

Options

A. It consists of a bony spiral canal that makes about `2 3/4` turns around
B. If contains three chambers, the upper scala vestibuli, middle scala media, and the lower scala tympani
C. The middle and lower chamber communicate through helicotroma
D. Cochlea contains 16000 to 24000 hair cells arranged in four rows

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks us to identify which statement about the cochlea is incorrect. We need to analyze each of the provided statements carefully.

2. **Analyzing Statement 1**: The first statement claims that the cochlea consists of a bony spiral canal that makes about 2 and 3/4 turns around.
- **Verification**: This is true. The cochlea indeed has a bony structure and typically makes about 2 and 3/4 turns.

3. **Analyzing Statement 2**: The second statement states that the cochlea contains three chambers: the upper scala vestibuli, the middle scala media, and the lower scala tympani.
- **Verification**: This is also true. The cochlea is divided into these three distinct chambers.

4. **Analyzing Statement 3**: The third statement claims that the middle and lower chambers communicate through helicotrema.
- **Verification**: This statement is incorrect. The helicotrema is the area where the upper chamber (scala vestibuli) and the lower chamber (scala tympani) communicate, not the middle chamber (scala media). Therefore, this statement is the one that is not correct.

5. **Analyzing Statement 4**: The fourth statement mentions that the cochlea contains around 16,000 to 24,000 hair cells arranged in four rows.
- **Verification**: This statement is true. The cochlea contains a significant number of hair cells that function as sound receptors.

6. **Conclusion**: After analyzing all statements, we find that the incorrect statement is the third one: "The middle and lower chamber communicate through helicotrema." Therefore, the answer is option C.

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