Barber Practice State Board Practice Exam

Which muscle surrounds the lower part of the lip?

1. Orbicularis Oris

2. Depressor Labii Inferioris

3. Buccinator

4. Risorius

The correct answer is: Depressor Labii Inferioris

The muscle that surrounds the lower part of the lip is specifically the Depressor Labii Inferioris. This muscle plays a crucial role in facial expressions, particularly by lowering the lip and drawing it slightly lateral. It is located at the lower lip and contributes to expressions of sadness or frowning. The Orbicularis Oris, while also involved in lip movement, encircles the entire mouth and is responsible for actions like puckering and closing the lips but does not specifically target just the lower lip. The Buccinator is primarily involved in compressing the cheeks against the teeth, which is more relevant to facilitating actions such as chewing rather than directly affecting the lower lip. Finally, the Risorius primarily assists in drawing the corners of the mouth sideways, contributing to expressions like smiling rather than focusing on the lower lip itself.