Corrugator supercilii muscle
Corrugator supercilii is a small, pyramidal muscle that belongs to the circumorbital and palpebral group of facial muscles, along with the levator palpebrae superioris and orbicularis oculi muscles. Like other facial muscles, corrugator supercilii is innervated by branches of the facial nerve.
Corrugator supercilii is a paired muscle found deep to the medial end of each eyebrow. Upon contraction, these muscles draw the two eyebrows together medially and inferiorly, thereby producing vertical wrinkles over the glabella and an expression of frowning.
This article will teach you all you need to know about the anatomy and functions of the corrugator supercilii muscle.
|Origin||Medial end of superciliary arches, Fibers of orbicularis oculi muscle|
|Insertion||Skin above middle of supraorbital margin|
|Function||Creates vertical wrinkles over glabella|
|Innervation||Temporal branches of facial nerve (CN VII)|
|Blood supply||Ophthalmic artery, superficial temporal artery|
Origin and insertion
Corrugator supercilii originates from the medial end of the superciliary arch of frontal bone, cranially to the root of the nose. Its fibers extend diagonally, laterally and slightly superiorly to insert into the skin of the eyebrow above the middle part of the supraorbital margin.
Corrugator supercilii is located superior to the orbit, extending diagonally over the supraorbital margin and the medial end of the eyebrow. As corrugator supercilii extends superolaterally, it is found deep to the orbicularis oculi muscle and the frontal belly of occipitofrontalis, partially blending with both. At its origin point, corrugator supercilii is found laterally adjacent to the procerus muscle.
Like other facial muscles, corrugator supercilii is innervated by the temporal branches of the facial nerve (CN VII)
The corrugator supercilii muscle receives arterial blood mainly from the ophthalmic artery, which stems from the internal carotid artery. A small portion of arterial blood is additionally provided by branches of the superficial temporal artery, which originates from the external carotid artery. Venous blood is drained from corrugator supercilii by the superior ophthalmic vein, which flows into the cavernous sinus.
Corrugator supercilii exerts traction on the skin above the supraorbital margin. The combined actions of the orbicularis oculi and corrugator muscle pull the eyebrows medially and inferiorly. This action can serve different functions, such as protecting the eyes from bright sunlight or rain. Due to its role in the facial expression of frowning, corrugator supercilii is deemed as the “eyebrow muscle” by producing vertical wrinkles over the glabella.