QUESTION:
- 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?
ANSWER:
- Primarily, the cranial nerves affected by the viral infection are the Facial Nerves (CN VII). These nerves are responsible for the movement of facial muscles for making expressions, which explains the loss of movement of the right side of her face. It is also responsible for taste from anterior two-thirds of tongue and palate. Additionally, the Glossopharyngeal Nerve (CN IX) providing taste to the posterior third of the tongue, and Vagus Nerve (CN X) providing fibers to the epiglottis region, are also affected nerves associated with taste. Moreover, the contraction of the orbicularis oculi mucle by the facial nerves also regulate the closing of eyes. Facial nerves also control stimulation and parasympathetic innervation of salivary glands (specifically the sublingual and submandibular glands). Also, the Glossopharyngeal Nerve (CN IX) supplies the providing gland. So when CNs VII and IX damaged, less saliva is produced, therefore causing dry mouth.
REFERENCES:
- Dry mouth. Physiopedia. (n.d.). https://www.physio-pedia.com/Dry_Mouth
- Gibbons, J. R., & Sadiq, N. M. (2023, May 1). Neuroanatomy, neural taste pathway - statpearls - NCBI bookshelf. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK545236/
- Tortora, G. J., & Derrickson, B. (2017). CHAPTER 14 The Brain and Cranial Nerves. In Principles of anatomy and physiology (15th ed., p. 488). essay, Wiley Custom Learning Solutions.