Muscle · Neck

Platysma

Musculus platysma

A broad, paper-thin sheet of muscle lying in the fat directly under the skin of the neck, spreading up from the upper chest and shoulder across the collarbone to the jawline and the corner of the mouth. It is a skin muscle rather than a joint muscle: at its upper end it blends into the skin and the muscles of the lower face instead of attaching to bone, so contracting it wrinkles and tenses the skin of the neck and drags the corner of the mouth down. That is what makes the two vertical cords stand out on the front of the neck when somebody grimaces, strains or braces. Being a muscle of facial expression, it is supplied by the facial nerve and not by any of the neck's own nerves.