The brachiocephalicus lies on the neck deep to the sphincter colli superficialis and platysma. It is a long, flat muscle that extends from intersection clavicularis between brachium and the head and neck. It contents on its deep part a claviuclar remnant.
This muscle is divided in three portions in carnivores, named by their relations hip to the clavicular intersection:
Origin: Clavicular tendon and the distal end of the cranial surface of the humerus.
Insertion: Dorsal surface of the neck.
Action: Bilateral fixation of the neck.