Your patient recently had a viral infection and now she cannot move the muscles on the right side of her face. In addition, she is experiencing a loss of taste and dry mouth and she cannot close her right eye. Which cranial nerves have been affected by the viral infection?
The viral infection that affected the patient resulted in the damage of one of the patient’s two facial nerves (7th cranial nerve), which performs both motor and sensory functions. This particular nerve section carries the nerve fibers that are responsible for controlling both facial movement and expression.
The facial nerves cover five branches that perform various distinct motor functions:
Frontal (temporal) branch – Controls the forehead muscles
Zygomatic branch – Closing of eyes
Buccal branch – Movement along the nose, lips, and mouth
Marginal mandibular branch – Drawing downwards of the lower lip and moderation of loud sound perception
Cervical branch – Movement in the chin and lower corners of the mouth
The facial nerve is involved in the following bodily processes:
- Controlling of muscles that help make facial expressions such as smiling, frowning, wrinkling of the nose, and raising of both the eyebrows and forehead
- Tasting with the use of the anterior 2/3 of the tongue
- Sending over taste information from the tongue to the brain
- Production of tears through the lacrimal gland
- Moderation of the noise volume sensitivity through the stapedius muscle
References:
What is the facial nerve? (n.d.). Stanford Facial Nerve Center. Retrieved October 7, 2022, from https://med.stanford.edu/ohns/OHNS-healthcare/facialnervecenter/about-the-facial-nerve.html
Facial Nerve (n.d.). Cleveland Clinic. Retrieved October 7, 2022, from https://my.clevelandclinic.org/health/body/22218-facial-nerve