If facial nerve is cut what will be the consequence?

Options

A. Smell sensation is lost
B. Dry mouth occur
C. Person can not express facial expressions
D. Mastication will not occur

Answer

### Step-by-Step Solution:

1. **Understanding the Facial Nerve**: The facial nerve, also known as cranial nerve VII, is primarily responsible for controlling the muscles of facial expression. It also has roles in taste sensation from the anterior two-thirds of the tongue and in the secretion of saliva and tears.

2. **Consequences of Cutting the Facial Nerve**:
- If the facial nerve is cut, the most immediate and significant consequence is the inability to control facial muscles. This means the person will not be able to express emotions such as happiness, sadness, anger, or surprise through facial expressions.
- Other functions associated with the facial nerve, such as taste sensation from the front part of the tongue and the secretion of saliva and tears, may also be affected, but the most noticeable consequence will be the loss of facial expressions.

3. **Analyzing the Options**:
- **Option 1: Smell sensation is lost** - This is incorrect because the sense of smell is controlled by the olfactory nerve (cranial nerve I), not the facial nerve.
- **Option 2: Dry mouth** - This is also incorrect. While the facial nerve does contribute to saliva production, dry mouth is more related to the function of other nerves, such as the glossopharyngeal nerve (cranial nerve IX).
- **Option 3: Person cannot express facial expressions** - This is the correct answer. Cutting the facial nerve leads to paralysis of the facial muscles, resulting in the inability to express emotions.
- **Option 4: Mastication will not occur** - This is incorrect. Mastication (chewing) is primarily controlled by the trigeminal nerve (cranial nerve V), not the facial nerve.

4. **Conclusion**: The correct consequence of cutting the facial nerve is that the person will not be able to express facial expressions.

### Final Answer:
The correct answer is: **The person cannot express facial expressions.**

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