The Platsma is the muscle out of which most facial muscles evolved. It runs from the upper chest area through the neck to the lower cheek area, originating in the fascia of the pectoral and deltoid regions and inserting into the mandible and several muscles such as triangularis. It lowers the lower jaw and lip, and tenses the neck to form noticable vertical and/or horizontal ridges and depressions in the neck.

Platysma is innervated by the deep cervical branch of the facial nerve (VII) and is supplied with blood by the suprascapular and facial arteries.