Corpus: Zygomaticus major muscle
from Greek: zygon - yoke, fork
1. Definition
The zygomaticus major muscle is a superficial muscle located in the cheek area, responsible for raising the corner of the mouth. It is part of the mimic musculature.
2. Course
The zygomaticus major muscle originates from the zygomatic bone, specifically at the anterior end of the temporal process, behind the zygomaticotemporal suture. Its fibers run medially and downward to insert at the modiolus, located at the corner of the mouth, and also into the upper lip.
3. Innervation
The zygomaticus major muscle is innervated by the zygomatic branches of the facial nerve (cranial nerve VII).
4. Function
The primary function of the zygomaticus major muscle is to lift the corner of the mouth, contributing to expressions such as smiling. Together with the risorius muscle, it plays a key role in laughing. The muscle is closely attached to the skin, which allows the skin to move with the muscle during facial expressions.