Anatomy Practice Exam

Which muscle is specifically responsible for puckering the lips?

1. Masseter

2. Orbicularis oris

3. Buccinator

4. Platysma

The correct answer is: Orbicularis oris

The muscle that is specifically responsible for puckering the lips is the orbicularis oris. This muscle is a complex structure of muscle fibers that encircles the oral cavity. Its primary function is to control movements of the lips, allowing for actions such as puckering, kissing, and other expressions that involve lip movement. When the orbicularis oris contracts, it causes the lips to come together and form a tight seal, or pucker. This capability is essential not only for facial expressions but also for functional activities like speaking, eating, and drinking. The positioning and function of this muscle make it uniquely suited for these tasks, setting it apart from the other muscles listed. Other muscles, while they may contribute to facial expressions and actions involving the mouth, do not specifically control the puckering motion. For example, the masseter is primarily involved in chewing, the buccinator helps to hold food in place while chewing, and the platysma is more associated with movements of the neck and lower face rather than the detailed control of the lips.