The platysma is a thin, broad muscle located in the neck and lower face. It extends from the upper chest and shoulder area, running up to the jawline. This muscle plays a role in facial expressions, particularly in movements that lower the jaw and pull down the corners of the mouth. Functionally, the platysma helps in various actions such as grimacing and expressing surprise or fear. It is innervated by the facial nerve, which controls many facial muscles. Understanding the platysma is important in fields like anatomy, cosmetic surgery, and physiotherapy.