Eustachian tube

Options

A. connects buccal cavity with middle ear
B. causes vibration in perilymph surrounding the ear ossicles
C. induces vibrations in tympanum
D. conducts sound wave from the auditory meatus to internal ear

Answer

### Step-by-Step Solution:

1. **Understanding the Eustachian Tube**: The Eustachian tube is a narrow passage that connects the middle ear to the nasopharynx (the upper part of the throat behind the nose). Its primary function is to equalize air pressure on both sides of the eardrum and to drain any fluid from the middle ear.

2. **Analyzing the Options**:
- **Option 1**: "Connects buccal cavity with middle ear."
- This statement is **incorrect**. The Eustachian tube connects the middle ear to the nasopharynx, not the buccal cavity.
- **Option 2**: "Causes vibration in Paralymph surrounding the Ear Ossicles."
- This statement is **incorrect**. The vibration in the perilymph is caused by the tympanic membrane, not the Eustachian tube.
- **Option 3**: "Induces vibration in tympanum."
- This statement is **incorrect**. The outer ear (pinna) induces vibration in the tympanic membrane (tympanum), not the Eustachian tube.
- **Option 4**: "Conduct sound waves from the auditory malleus to internal ear."
- This statement is **incorrect**. The Eustachian tube does not conduct sound waves; it primarily functions to equalize pressure.

3. **Conclusion**: After analyzing all the options, it is clear that the first option is the only one that is correct. However, it is important to note that the Eustachian tube does not connect the buccal cavity to the middle ear; it connects the middle ear to the nasopharynx.

### Final Answer:
The correct statement regarding the Eustachian tube is that it connects the middle ear to the nasopharynx, not the buccal cavity.