The levator labii superioris (pl. ''levatores labii superioris'', also called quadratus labii superioris, pl. ''quadrati labii superioris'') is a

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of mus ...

of the

human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a hea ...

used in facial expression. It is a broad sheet, the origin of which extends from the side of the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passe ...

to the zygomatic bone.

Structure

Its medial fibers form the ''angular head'' (also known as the levator labii superioris alaeque nasi muscle,) which arises by a pointed extremity from the upper part of the frontal process of the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...

and passing obliquely downward and lateralward divides into two slips. One of these is inserted into the greater alar cartilage and skin of the nose; the other is prolonged into the lateral part of the upper lip, blending with the infraorbital head and with the

orbicularis oris In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth. It is a sphincter, or circular muscle, but it is actually composed of four independent quadrants that interlace and give only an appearance ...

. The intermediate portion or ''infraorbital head'' arises from the lower margin of the

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...

immediately above the infraorbital foramen, some of its fibers being attached to the

, others to the zygomatic bone. Its fibers converge, to be inserted into the muscular substance of the upper lip between the angular head and the levator anguli oris. The lateral fibers, forming the ''zygomatic head'' (also known as the zygomaticus minor muscle) arise from the malar surface of the zygomatic bone immediately behind the zygomaticomaxillary suture and pass downward and medialward to the upper lip.

Function

Its main function is to elevate the upper lip.Clinically Oriented Anatomy 6th ed by Moore & Dalley

Additional images

File:Sobo 1909 262.png File:Sobo 1909 264.png File:Gray157.png, Left maxilla. Outer surface. File:Gray165.png, Left zygomatic bone. Malar surface. File:Gray508.png, The arteries of the face and scalp. File:Frontalis muscle animation small.gif

References

External links

PTCentral
{{Authority control Muscles of the head and neck

Structure

Function

See also

Additional images

References

External links