Sacrum The number of sacral vertebrae varies slightly. For instance, the S1S5 vertebrae of a horse will fuse, the S1S3 of a dog will fuse, and four pelvic vertebrae of a rat will fuse between the lumbar and the caudal vertebrae of its tail. The "Stegosaurus" dinosaur had a greatly enlarged neural canal in the sacrum, characterized as a "posterior brain case”. The sacrum is a complex structure providing support for the spine and accommodation for the spinal nerves. It also articulates with the hip bones. The sacrum has a base, an apex, and three surfaces – a pelvic, dorsal and
History of beliefs about the human body History of beliefs about the human body The human body has been subject of much debate. How people are defined, and what defined them – be it their anatomy or their energy or both – depends on culture and time. Culture not only defines how sex is perceived but also how gender is defined. Today gender, sex, and identity continue to be of much debate and change based on what place and people are being examined. The early modern idea of the body was a cultural ideal, an understanding and approach to how the body works and what place that