Platysma

The platysma (Latin: platysma) is a broad and flat neck muscle extending from the lower part of the face to the upper thorax. It is classified as the superficial neck muscle. The platysma is a paired thin muscle arising from the upper parts of the shoulders and inserting into the mouth area. It also belongs to the anterior neck muscles. The platysma partly covers the pectoralis major and deltoid muscles. In the mouth area, it divides into three parts - mandibular, labial and modiolar (nodular).

Origin

The platysma originates from the skin over the lower neck and upper lateral and anterior chest areas. It also originates from the fascia covering the clavicle, pectoralis major and deltoid muscles.

Insertion

The platysma inserts on the base of the mandible and into the skin covering structures of the lower face and angle of the mouth.

Action

Contractions of the platysma tense and wrinkle skin of the lower face and neck regions. This muscle also contributes to forced depression of the mandible and angle of the mouth.

Innervation

The platysma is innervated by the cervical branch of the facial nerve (CN VII).

Blood supply

The platysma receives arterial blood supply from the submental artery of the facial artery and suprascapular artery arising from the thyrocervical trunk.