The |nasalis| muscle consists of two parts: the alar and the ~transverse~. The alar is used when the nostrils are flared and runs along the side of the |nose|. The ~transverse~ runs diagonally and is used to wrinkle the |nose|. The |nasalis| is composed of three small muscles: the compressor nasi, the |dilator naris posterior|, and the |depressor septi nasi|. The compressor nasi is a small, thin muscle with a triangular shape. It runs along the bridge of the |nose| and depresses the ~cartilage~ and compresses the alae together. The depressor nasi is a short muscle that lies between the musclular structure and the |mucous membrane| of the lip. It arises from the upper lip and extends to be inserted into the |septum| of the |nose|. It constricts the |nares| (nostrils) of the |nose|, the opposite action of the compressor nasi muscle. The dilator |nares| ~posterior~ is a small muscle that originates from the edge of the nasal notch and is inserted into the skin near the edge of the nostril. This muscle works with the dilator naris ~anterior~, which is located in front of it, to dilate the opening of the |nares| (nostrils). All muscles of the |nose| are supplied by the facial ~nerve~.
