Macroscopic anatomy of the plexus brachialis and its innervation in the common pheasant (Phasianus colchicus)

The present study was conducted to describe the detailed features of the anatomical structure of the plexus brachialis and its branching nerves in the common pheasant (Phasianus colchicus). Five adult birds were used. The animals were killed by cutting the common carotid artery and dissection was performed bilaterally under a stereomicroscope. The plexus brachialis was a single plexus with a rather simple structure consisting of ventral rami of the last two cervical (C13) and (C14) and first thoracic vertebrae (T1). The accessory plexus brachialis was not present. The ventral branches united by exchanging nerve fibers. The nerves originating from the dorsal cord in the common pheasant were n. axillaris, n. anconealis, n. radialis, and n. subscapularis, which are responsible for innervating the wing extensor musculature, and n. medianoulnaris, n. pectoralis, n. supracoracoideus, n. bicipitalis, and n. coracobrachialis emerging from the ventral cord for dispersing into the flexor muscles. In conclusion, the anatomy of the plexus brachialis in the common pheasant displayed some similarities and differences as compared to other species. Despite the similarities in the nerves emerging from the plexus brachialis of common pheasant and other bird species, its nerves are composed of ventral branches of the spinal nerves which differ from other avian species.