Alberta Written Barber Practice Exam

Which part of the nervous system is primarily responsible for facial expressions?

1. Cranial nerves

2. Spinal nerves

3. Autonomic nervous system

4. Sympathetic nervous system

The correct answer is: Cranial nerves

The cranial nerves are primarily responsible for facial expressions because they directly innervate the muscles of facial expression. Particularly, the facial nerve, also known as the seventh cranial nerve, plays a crucial role in controlling the movements of the muscles that allow us to express a range of emotions through facial gestures. This includes smiling, frowning, and other expressions that convey feelings. The spinal nerves are involved in sensation and motor function in the limbs and trunk, but they do not directly contribute to facial expressions. The autonomic nervous system regulates involuntary functions such as heart rate and digestion, rather than voluntary muscle movements like those required for facial expressions. The sympathetic nervous system, a part of the autonomic system, is specifically responsible for the body’s fight-or-flight response, which does not include the control of facial musculature. Thus, cranial nerves, and especially the facial nerve, are essential for facilitating the full range of human facial expressions.