The brain, the The main nerve trunk running down the spinal canal and connecting the individual’s mind and consciousness to the rest of his or her body. It is about the size of a person’s little finger, in diameter. It cannot repair itself if damaged. and the nerves that connect these structures to all parts of the body can be referred to as neural elements, to distinguish them from other parts, in particular their protective coverings, such as the These are membranes which enclose the brain and the spinal cord. There are three, which are very different from one another in nature. The dura is the outermost, lining the inside of the skull and the spinal canal. It is tough and waterproof, retaining the cerebrospinal fluid that bathes the brain and spinal cord. The innermost layer is the pia, which is like a thin skin applied closely to the surface of the brain and spinal cord. Between these two layers is the arachnoid, which is a loose, net-like structure made up of sheets and strands of thin, translucent material, stretching between the dura and the pia. The cerebrospinal fluid flows along the subarachnoid channels, between the arachnoid and the... and When we think about the spine, we need to consider both the bones and the ligaments that hold them together, as well as the spinal cord and the nerves that issue from it. The spinal cord and nerves together make up the neural elements. The bones and ligaments are the skeletal elements..