Zygomaticus major is a facial muscle that is primarily responsible for elevating the corners of the mouth during smiling. Some synonyms for this muscle include the zygomaticus muscle, the zygomaticus minor muscle, and the risorius muscle. The zygomaticus minor muscle is also involved in smiling, while the risorius muscle helps to retract the corners of the mouth. These muscles work together to create various expressions, from a genuine smile to a forced grin. Understanding the body's anatomy can help individuals better understand how different muscles work together to produce different movements and facial expressions.