The procerus muscle (or pyramidalis nasi) is a small pyramidal slip of muscle deep to the superior orbital nerve,

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

and

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenat ...

. ''Procerus'' is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

, meaning tall or extended.

Structure

The procerus muscle arises by tendinous fibers from the fascia covering the lower part of the nasal bone and upper part of the

lateral nasal cartilage The lateral cartilage (upper lateral cartilage, lateral process of septal nasal cartilage) is situated below the inferior margin of the nasal bone, and is flattened, and triangular in shape. Its anterior margin is thicker than the posterior, and ...

. It is inserted into the skin over the lower part of the forehead between the two

eyebrows An eyebrow is an area of short hairs above each Human eye, eye that follows the shape of the lower margin of the Supraorbital ridge, brow ridges of some mammals. In humans, eyebrows serve two main functions: first, human communication, communica ...

on either side of the midline, its fibers merging with those of the

frontalis muscle The frontalis muscle () is a muscle which covers parts of the forehead of the skull. Some sources consider the frontalis muscle to be a distinct muscle. However, Terminologia Anatomica currently classifies it as part of the occipitofrontalis muscle ...

Nerve supply

The procerus muscle is supplied by the temporal branch of the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste ...

(VII). It may also be supplied by other branches of the facial nerve, which can be varied.

Function

The procerus muscle helps to pull that part of the skin between the eyebrows downwards, which assists in flaring the

nostrils A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

. It can also contribute to an expression of

anger Anger, also known as wrath or rage, is an intense emotional state involving a strong uncomfortable and non-cooperative response to a perceived provocation, hurt or threat. A person experiencing anger will often experience physical effects, su ...

. Procerus is supplied by temporal and lower zygomatic branches from the

. A supply from its buccal branch has also been described. Its contraction can produce transverse wrinkles.

Clinical significance

Procerus sign

Dystonia of the procerus muscle is involved in the

procerus sign The procerus sign (vertical wrinkling of the forehead) is a medical sign consisting of vertical forehead wrinkling around the bridge of the nose and the glabella. This can be seen in neurodegenerative diseases such as progressive supranuclear ...

, which is indicative of

progressive supranuclear palsy Progressive supranuclear palsy (PSP) is a late-onset degenerative disease involving the gradual deterioration and death of specific volumes of the brain. The condition leads to symptoms including loss of balance, slowing of movement, difficulty ...

(PSP).

Denervation

The procerus muscle may be denervated to reduce furrow lines around the

glabella The glabella, in humans, is the area of skin between the eyebrows and above the nose. The term also refers to the underlying bone that is slightly depressed, and joins the two brow ridges. It is a cephalometric landmark that is just superior to ...

caused by

frowning A frown (also known as a scowl) is a facial expression in which the eyebrows are brought together, and the forehead is wrinkled, usually indicating displeasure, sadness or worry, or less often confusion or concentration. The appearance of a frow ...

. This may be for cosmetic purposes. Surgery can be used to transect the temporal branch of the

, although other branches of the facial nerve may also need to be cut.

References

Additional Images

File:Procerus muscle animation small.gif, Procerus muscle (red). {{Authority control Muscles of the head and neck