Epicranius Muscle

The epicranius muscle covers the upper part of the cranium and consists of two muscular parts: the "frontalis," which lies over the frontal bone, and the "occipitalis," which lies over the occipital bone. These parts are united by a broad, tendinous membrane called the "epicranial aponeurosis," which covers the cranium like a cap. Contraction of the epicranius raises the eyebrows and causes the skin on the forehead to wrinkle horizontally, as when a person expresses surprise. Headaches often result from the continual contraction of this muscle.