Which is thickened to form organ of corti ?

Options

A. Tectorial membrane
B. Reissner's membrane
C. Basilar membrane
D. All of the above

Answer

To answer the question "Which is thickened to form the organ of Corti?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Organ of Corti**:
- The organ of Corti is a crucial structure located in the inner ear. It serves as the receptor organ for hearing and is often referred to as the body's microphone.

2. **Identifying the Location**:
- The organ of Corti is situated on the basilar membrane, which is part of the cochlea in the inner ear.

3. **Reviewing the Membranes**:
- There are three membranes to consider: the tectorial membrane, the resinous membrane, and the basilar membrane.
- The tectorial membrane is an extracellular connective tissue that is associated with the organ of Corti but does not thicken to form it.
- The resinous membrane is located inside the cochlea and separates the cochlear duct from the vestibular duct, but it also does not contribute to the formation of the organ of Corti.

4. **Identifying the Correct Membrane**:
- The basilar membrane is the structure that thickens to form the organ of Corti. It acts as the floor of the cochlear duct and supports the sensory cells of the organ of Corti.

5. **Conclusion**:
- Therefore, the correct answer to the question is the basilar membrane, as it is the membrane that thickens to form the organ of Corti.

### Final Answer:
The basilar membrane is thickened to form the organ of Corti.

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