Platysma

Platysma is a superficial muscle that is located in the anterior region of the neck. It is a broad sheet-like muscle that plays a role in facial expression and is part of the muscles of facial expression.

Anatomy

The platysma muscle originates from the fascia covering the superior parts of the pectoralis major and deltoid muscles. It extends upward and medially along the sides of the neck and inserts into the lower border of the mandible, the skin of the lower face, and the corner of the mouth.

Innervation

The platysma is innervated by the cervical branch of the facial nerve (cranial nerve VII). This nerve is responsible for the motor control of the muscle, allowing it to perform its functions.

Function

The primary function of the platysma is to depress the lower jaw and the corners of the mouth, which contributes to expressions of sadness or fright. It also helps to tense the skin of the neck, which can be observed when a person grimaces.

Clinical Significance

Damage to the facial nerve can result in paralysis of the platysma, leading to asymmetry in facial expressions. Surgical procedures in the neck region, such as neck dissection or thyroidectomy, must take care to avoid damaging the cervical branch of the facial nerve to preserve the function of the platysma.

Related Pages

• Muscles of facial expression
• Facial nerve
• Mandible
• Pectoralis major
• Deltoid muscle
• Neck dissection
• Thyroidectomy