procerus /prəsir″əs/ [L, stretched] , one of three muscles of the nose. It is a small pyramidal muscle that arises from the fascia of the nasal bone and the lateral nasal cartilage and inserts into the skin over the lower part of the forehead between the eyebrows. It is innervated by buccal branches of the facial nerve. The procerus functions to draw down the eyebrows and wrinkle the nose. Compare depressor septi, nasalis.
