Epicranius, also known as the frontal belly, is a muscle located in the forehead region. It is responsible for raising the eyebrows and creating facial expressions such as surprise or concern. The muscle originates from the epicranial aponeurosis, which is a tough layer of connective tissue covering the cranium.
When the Epicranius muscle contracts, it pulls the scalp backward and raises the eyebrows. This action creates the appearance of wrinkles on the forehead and a surprised or concerned expression on the face.
The antagonist muscle of the Epicranius is the orbicularis oculi, which is responsible for closing the eyelids and squinting. These two muscles work together to create a range of facial expressions and control the movement of the eyebrows and eyelids.