The muscles of facial expression are a group of muscles that allow us to convey emotions through our faces. These muscles are primarily located beneath the skin of the face and are responsible for movements such as smiling, frowning, and raising eyebrows. They are innervated by the facial nerve, which controls their contractions. These muscles include the orbicularis oculi, which helps close the eyes, and the zygomaticus major, which pulls the corners of the mouth upward when smiling. Other important muscles include the frontalis, which raises the forehead, and the platysma, which can create expressions of surprise or fear.