The procerus is a small pyramidal slip of muscle deep to the superior orbital nerve, artery and vein. Procerus is Latin, meaning tall or extended.
The procerus arises by tendinous fibers from the fascia covering the lower part of the nasal bone and upper part of the lateral nasal cartilage.
It is inserted into the skin over the lower part of the forehead between the two eyebrows on either side of the midline, its fibers merging with those of the frontalis.
The procerus helps to pull that part of the skin between the eyebrows downwards, which assists in flaring the nostrils. It can also contribute to an expression of anger.
Procerus is supplied by temporal and lower zygomatic branches from the facial nerve. A supply from its buccal branch has also been described. Its contraction can produce transverse wrinkles.
This article incorporates text in the public domain from page 382 of the 20th edition of Gray's Anatomy (1918)