Vestibular and tympanic canals of cochlea are connected by

Options

A. Oval window
B. Round window
C. Helicotrema
D. Eustachial canal.

Answer

To solve the question regarding how the vestibular and tympanic canals of the cochlea are connected, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structures**: Understand that the cochlea has three main canals: the vestibular canal (scala vestibuli), the tympanic canal (scala tympani), and the cochlear duct (scala media).

2. **Understand the Function of the Canals**: The vestibular canal is involved in the transmission of sound waves from the oval window, while the tympanic canal is involved in the dissipation of sound waves through the round window.

3. **Locate the Connection**: The question asks for the connection between the vestibular canal and the tympanic canal.

4. **Identify the Correct Structure**: The structure that connects the vestibular canal and the tympanic canal is known as the helicotrema. This structure is located at the apex of the cochlea.

5. **Eliminate Incorrect Options**:
- **Oval Window**: This is the membrane-covered opening that leads from the middle ear to the vestibular canal but does not connect the two canals.
- **Round Window**: This is another membrane-covered opening that allows fluid movement in the cochlea but does not connect the two canals.
- **Eustachian Canal**: This connects the middle ear to the pharynx and is not related to the cochlear canals.

6. **Conclude the Answer**: Since the helicotrema is the only structure that connects the vestibular canal and the tympanic canal, the correct answer is **C) helicotrema**.

### Final Answer:
The vestibular and tympanic canals of the cochlea are connected by **helicotrema**.

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