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 Yang Qi energy where as a female has dominant Yin energy. Transgenderism, hermaphroditism and other variations of the body can be explained by the Yin and Yang Qi ideas of the body much better than the European counterparts. Other types of change in the world were classified by Wood, Fire, Earth, Metal and Water. Applied to the body these 5 forces were the Liver, Heart, Spleen, Lung, and Kidney. These representations of the physical world in the body was understood dynamically and represents a deeper connection to the non animate objects and surroundings of a human. The body was not