Zygomaticus muscle

There is only one zygomatic muscle on each side in domestic animals (M. zygomaticus). It is the equivalent of the muscle zygomaticus major in Men; the zygomaticus minor, absent in domestic Mammals, is besides inconstant in Men.

Conformation: it is a large thin fleshy strip spread on the surface of the masseter and buccinator muscles from the zygomatic region until the commissure of the lips. Its caudal extremity is aponevrotic in Ungulates.

Insertions: It originates in principle on the facial crest, at the rostral part of the zygomatic bone (Men) or on the adjacent part of the superficial aponevrosis of the masseter (Equidae). But this attach can be reported much more caudally, near the temporomandibular joint (Ruminants, Pigs), or to the base of the ear, on the scutiform cartilage (Carnivorous) or even on the auricle (Rabbit). The end reaches the angle of the mouth, on the orbicular muscle of the mouth, or the surface of the buccinator muscle (Equidae), to some distance of the commissure.

Function:It pulls the commissure of the lips upward and backward.