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 oxygenate ...
. ''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 ...
, 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 organ ...
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
An eyebrow is an area of short hairs above each eye that follows the shape of the lower margin of the brow ridges of some mammals. In humans, eyebrows serve two main functions: first, communication through facial expression, and second, preve ...
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 muscl ...
.
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
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 tur ...
. 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, suc ...
.
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 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 caused by
frowning.
This may be for
cosmetic
Cosmetic may refer to:
* Cosmetics, or make-up, substances to enhance the beauty of the human body, apart from simple cleaning
*Cosmetic, an adjective describing beauty, aesthetics, or appearance, especially concerning the human body
*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).
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Muscles of the head and neck