What action does the corrugator muscle perform?

The corrugator muscle primarily functions to draw the eyebrows downward and together, which creates vertical furrows between the brows. This action is commonly associated with frowning or expressing a feeling of concern or concentration. Understanding the role of the corrugator muscle is important in esthetics, particularly when considering facial expressions and their impact on cosmetic procedures or treatments, such as botox, which is often used to relax this muscle and reduce the appearance of frown lines.

In this context, other options do not pertain to the corrugator muscle's function. Closing and opening the eyelids is associated with the orbicularis oculi muscle, while raising the upper lip involves the zygomaticus muscle and other muscles of facial expression. Therefore, recognizing the specific actions of facial muscles is crucial for effective esthetic practices and understanding client concerns.