(From complecto,to comprise). Called also trigeminus. This muscle runs obliquely, rising from the transverse processes of the six inferior cervical vertebrae: and sixth, seventh, or eighth superior dorsal verterbrae: it then directs its course upwards, and is inserted into the cavity, below the transverse line of the occiput, and bends the head back. It sometimes re-'•eives a few slips from the spinal processes of some of the vertebrae of the dorsum. The complexus being removed, we see the two recti and the two obliqui.
Complexus minor, called also mastoidaeus lateralis, trachelo-mastoidtcus, et capitis, par tertium Fallopii. When the splenius muscle is removed, we see the complexus and the complexus minor; the complexus is nearer the spine, and the complexus minor is under the upper edge of the splenius; it is various in different bodies.
Albinus describes its origin twelve different ways: it rises from the transverse processes of the three uppermost vertebrae of the back, and from the five lowermost of the neck, where it is connected to the transversalis cervicis, by as many thin tendons, which unite into a belly, and run up under the splenius. It is inserted into the middle of the posterior side of the mastoid process by a thin tendon. Its use is to assist the complexus, but it pulls the head more to one side. Innes.