Which cranial nerve is responsible for facial expression?

The cranial nerve responsible for facial expression is the facial nerve, also known as cranial nerve seven. This nerve innervates the muscles of facial expression, allowing for movements such as smiling, frowning, and other expressive actions. It originates in the brainstem and travels through the facial canal to reach the face, where it branches out to control various muscles.

Its primary function is to facilitate voluntary movements of the facial muscles, and it also plays a role in other functions such as taste sensation for the anterior two-thirds of the tongue and parasympathetic functions like saliva and tear production. Therefore, the identification of cranial nerve seven as the responsible nerve for facial expression is accurate and highlights its crucial role in both motor and sensory functions of the face.