Which cranial nerve is primarily responsible for motor control of facial expressions?

Cranial nerve VII, also known as the facial nerve, is primarily responsible for controlling the muscles involved in facial expressions. This nerve innervates most of the muscles of facial expression, which allow for a variety of actions such as smiling, frowning, and raising one's eyebrows. In addition to motor function, the facial nerve is also involved in taste sensations from the anterior two-thirds of the tongue and provides certain autonomic functions, such as secretions of saliva and tears.

The facial nerve has a unique pathway and branches extensively to reach various muscles of the face, highlighting its critical role in expressing emotions and performing facial movements. Damage to this nerve can lead to facial drooping or loss of the ability to perform facial expressions, illustrating its importance in motor control of the face.