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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 p ...
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 oxygenated ...
. ''Procerus'' is
Latin Latin (, or , ) is a classical language belonging to the Italic languages, 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 ...
, meaning tall or extended.


Structure

The procerus muscle arises by tendinous fibers from the
fascia A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal or ...
covering the lower part of the
nasal bone The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose. Ea ...
and upper part of the lateral nasal cartilage. It is inserted into the skin over the lower part of the
forehead In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the fore ...
between the two eyebrows 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 mus ...
.


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


Clinical significance


Procerus sign

Dystonia Dystonia is a neurological hyperkinetic movement disorder in which sustained or repetitive muscle contractions result in twisting and repetitive movements or abnormal fixed postures. The movements may resemble a tremor. Dystonia is often int ...
of the procerus muscle is involved in the procerus sign, 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 ...
caused by frowning. This may be for cosmetic purposes. Surgery can be used to transect 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 ta ...
, 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