Formation of the plexus sacralis in pheasants (Phasianus colchicus mongolicus) and macroanatomic investigation of the nerves originating from the plexus sacralis

Abstract

The purpose of this study was to investigate the formation of the plexus sacralis in the Kyrgyz pheasant (Phasianus colchicus mongolicus) and the origin of the nerves emerging from the plexus sacralis. Five adult male Kyrgyz pheasants were used that had been hunted in their natural habitat near the town of Tokmok in the Chuy region of Kyrgyzstan. The plexus sacralis was found to be formed in the lumbar region by the ventral strands of sacral nerves 1 to 5, originating in the spinal cord. The plexus is composed of the truncus cranialis, which consists of the ventral strands of the first 3 nerves united in the fossa renalis region, the truncus medianus formed by the ventral strand of the 4th nerve alone, and the truncus caudalis formed by the strand of the 5th ventral nerve alone. These 3 trunci are united to form the nervus ischiadicus at the entrance to the foramen ischiadicum. After passing through the foramen ischiadicum, the nerve separates into 5 strands as follows: the 1st strand forms the joint root of n. tibialis and n. peroneus, the 2nd strand forms the n. coxalis caudalis, the 3rd and 5th strands form the rr. musculares, and the 4th strand forms the n. cutaneus femoris caudalis.