platysma

platysma /pla·tys·ma/ (plah-tiz´mah) a platelike muscle that originates from the fascia of the cervical region and inserts in the mandible and the skin around the mouth. It wrinkles the skin of the neck and depresses the jaw.

---

pla·tys·ma (pl-tzm)

n. pl. pla·tys·mas or pla·tys·ma·ta (-m-t)

A platelike muscle in the neck extending to the lower face with origin from the subcutaneous layer and fascia covering the greater pectoral and deltoid muscles at the level of the first or second rib, with insertion to the mandible, the risorius muscle and platysma of the opposite side, with nerve supply from a branch of the facial nerve, and whose action depresses the lower lip and wrinkles the skin of the neck and the upper chest.

---

platysma

[plətiz′mə]

Etymology: Gk, platys, broad

one of a pair of platelike, wide muscles at the side of the neck. It arises from the fascia covering the superior parts of the pectoralis major and the deltoideus, crosses the clavicle, and rises obliquely and medially along the side of the neck. The platysma covers the external jugular vein as the vein descends from the angle of the mandible to the clavicle. The platysma is innervated by the cervical branch of the facial nerve and serves to draw down the lower lip and the corner of the mouth. When the platysma fully contracts, the skin over the clavicle is drawn toward the mandible, increasing the diameter of the neck.

---

platysma

the superficial sheet of cutaneous muscle over the face and neck.