Levator labii superioris muscle :-
Muscle details :-
The levator labii superioris (or quadratus labii superioris) is a muscle of the human body used in facial expression. It is a broad sheet.
- The levator labii superioris (or quadratus labii superioris) is a muscle of the human body used in facial expression. It is a broad sheet, the origin of which extends from the side of the nose to the zygomatic bone.
The levator labii superioris muscle has three points of origin that blend and pass into the upper lip.
- The angular head – levator labii superioris alaeque nasi – arises via the frontal process of the maxilla.
The infraorbital head arises via the inferior orbital margin, it is the largest part.
The zygomatic head – zygomaticus minor – arises via the facial portion of the zygomatic bone.
All three origins attach together within the upper lip and at the time of contraction, raise the upper lip . A strap of the angular head attaches within the ala of the nose and assists in dilation of the nostril.
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.
- Superficial fibers attach to the skin of the nasolabial furrow, just lateral towards the wing of the nose. Other fibers travel inferiorly past the furrow and constantly attaching up towards the red lip portion within the deep surface of the skin of the upper lip.
Middle fibers continue inferiorly just inferior to and parallel to the superficial layer. Then travels in the middle of the red lip as well as outer portions of the orbicularis oris, and attaches on the inside of the lip at the point where the dry red portion of the lip joins the moist mucous membrane, as well as within the red portion itself.
Deep fibers pierce the mass of the outer portion of the orbicularis, while it attaches at various points into the mucous membrane within the mouth.