PSI Barbering Practice Exam 2026 – 400 Free Practice Questions to Pass the Exam

The zygomaticus muscle is indeed a key player in the muscles responsible for facial expressions. Specifically, it consists of two parts, the zygomaticus major and zygomaticus minor, which are situated in the cheek area. The primary function of these muscles is to facilitate smiling and other expressions related to happiness or pleasure by raising the corners of the mouth. Their connection to the zygomatic bone allows for effective manipulation of facial expressions, making them central to non-verbal communication.

In contrast, the deltoid muscle is primarily associated with shoulder movement, the quadriceps group is involved in knee extension and is located in the thigh, and the serratus anterior muscle plays a role in the movement of the scapula. These muscles do not have any direct function in facial expressions, which is why they are not the correct choice in this context.