Answer
Facial nerve ( CN VII) injury affects the special senses o taste, hearing and smell;
The nasal epithelia and connective supporting tissues and the olfactory glands are innervated by the facial nerve. If facial nerve input is missing or decreased , the following results will take place:
1 Mucus production will decrease. Mucus is necessary for the dissolving and detection of odorants.
Therefore, the sense of smell will be diminished.
2. Taste buds in the anterior two-thirds of the tongue will be affected.
Consequently, the sense of taste will be impaired.
Work Step by Step
3. The stapedius muscle which is attached to the stapes is also innervated by the facial nerve.
Hearing may be impaired if CN VII is damaged. Contractions of the stapedius protects the inner ear from
the injury by prolonged loud sounds. Damage to CN VII results in increased susceptibility to hearing loss
due to excessively loud sounds.
