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
Artificial bone Artificial bone Artificial bone refers to bone-like material created in a laboratory that can be used in bone grafts, to replace human bone that was lost due to severe fractures, disease, etc. Bone fracture, which is a complete or partial break in the bone, is a very common condition that has more than three million US cases per year. Human bones have the ability to regenerate themselves by cycle of bone resorption and bone formation. The cell responsible for bone resorption is osteoclast, while the cell responsible for bone formation is osteoblast. That being said, the human body can regenerate