The procerus muscle (or pyramidalis nasi) is a small pyramidal muscle in the glabella. It is involved in

facial expression Facial expression is the motion and positioning of the muscles beneath the skin of the face. These movements convey the emotional state of an individual to observers and are a form of nonverbal communication. They are a primary means of conveying ...

s such as frowning and those associated with

attentional control Attentional control, commonly referred to as concentration, refers to an individual's capacity to choose what they pay attention to and what they ignore. It is also known as endogeny, endogenous attention or executive functions, executive attenti ...

, and it indirectly helps shield the eyes from bright light. Because it contributes to wrinkle formation on the nasal bridge, it is often targeted in non-surgical facial rejuvenation treatments, such as

botulinum toxin Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon en ...

injections. ''Procerus'' is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

, meaning tall or extended.

Structure

The procerus muscle arises by tendinous fibers from the

fascia A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. ...

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. Eac ...

and upper part of the

lateral nasal cartilage The lateral nasal 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 ...

. 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 fo ...

between the two eyebrows on either side of the midline, its fibers merging with those of the frontalis 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 ta ...

(VII). It may also be supplied by other branches of the facial nerve, which can be varied, including the lower zygomatic branches. A supply from its buccal branch has also been described. Its contraction can produce transverse wrinkles.

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 (emotion), 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 experie ...

Clinical significance

Procerus sign

Dystonia Dystonia is a neurology, neurological Hyperkinesia, hyperkinetic Movement disorders, movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed po ...

of the procerus muscle is involved in the procerus sign, which is indicative of progressive supranuclear palsy (PSP).

Denervation

The procerus muscle may be denervated to reduce furrow lines around the glabella caused by frowning. 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.

Additional images

File:Procerus muscle animation small.gif, Procerus muscle (red).

References

{{Authority control Muscles of the head and neck Human head and neck Facial muscles