Proper air pressure in the middle and internal ear is maintained by

Options

A. ear ossicles
B. tympanum
C. eustachian tube
D. cochlea

Answer

To solve the question "Proper air pressure in the middle and internal ear is maintained by," we will analyze the options provided and determine which one is correct.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which structure is responsible for maintaining proper air pressure in the middle and internal ear.

2. **Evaluating Option 1 - Ear Ossicles**:
- The ear ossicles consist of three small bones: malleus, incus, and stapes.
- Their primary function is to amplify sound waves and transmit them to the cochlea.
- **Conclusion**: This option is incorrect as ear ossicles do not maintain air pressure.

3. **Evaluating Option 2 - Tympanum (Tympanic Membrane)**:
- The tympanic membrane, also known as the eardrum, vibrates in response to sound waves and aids in hearing.
- It does not play a role in regulating air pressure.
- **Conclusion**: This option is also incorrect.

4. **Evaluating Option 3 - Eustachian Tube**:
- The Eustachian tube connects the middle ear to the nasopharynx (the upper throat).
- Its primary function is to equalize air pressure on both sides of the tympanic membrane, thus maintaining proper air pressure in the middle ear.
- **Conclusion**: This option is correct.

5. **Evaluating Option 4 - Cochlea**:
- The cochlea is a spiral-shaped organ in the inner ear that converts sound vibrations into neural signals.
- It does not have a role in maintaining air pressure.
- **Conclusion**: This option is incorrect.

### Final Answer:
The correct answer is **Option 3 - Eustachian Tube**.

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