The platysma muscle is a thin, broad muscle located in the neck and lower face. It originates from the upper chest and shoulder area, extending upward 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 actions such as grimacing and expressing surprise or fear. It is innervated by the facial nerve, which is responsible for controlling most facial muscles. The platysma also contributes to the overall appearance of the neck and can be involved in various cosmetic procedures.