The lowermost part of the lowest ventricle of the brain. During development the central canalThe central nervous system develops, in the womb, from a strip of tissue, passing along the back of the embryo, and which then rolls itself into a tube before sinking below the skin surface. This primitive neural tube then develops into the central nervous system, made up of the brain and the spinal cord. In the fully developed adult (i.e. by the age of about 18) the original tubular configuration of the embryonic structure is represented by chambers in the centre of the brain, known as ventricles. In the spine, the tubular structure is all-but obliterated, as the spinal cord develops, being represented by just a narrow tube in the centre of the cord, known as the central canal. of the spinal cordThe 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. is in continuity with the ventricular system at this point. It was once considered that syringomyeliaA cavity, within the spinal cord, which is filled with cerebrospinal fluid. Syringomyelia cavities come in various “shapes and sizes”, from short, spindle-shaped cavities through to long, tense cavities extending throughout the greater part of the spinal cord. Read more cavities usually fill from the ventricular system via the obex. This is no longer thought to be the filling mechanismThis term refers to the process by which fluid accumulates inside syringomyelia cavities. Many theories exist, backed by varying degrees of experimental or radiological evidence, but none explains how all the different types of cavities form. in most cases but it may still operate in some circumstances.