What is the primary function of the platysma muscle?

The primary function of the platysma muscle is to assist in facial expressions. This muscle is thin and broad, located in the neck and lower face, allowing it to help create various expressions, especially those involving the lowering of the jaw and the depressed position of the corners of the mouth. It plays a significant role in expressing emotions such as surprise, disgust, or tension.

While the platysma does have a minor role in neck movement, its main contribution is in facial expressions rather than mobility. Other functions like supporting breathing are more associated with different muscles in the respiratory system instead of the platysma's primary actions. Similarly, flexing the arm is a function of muscles in the upper limb, clearly distinct from the role of the platysma in facial dynamics.