Narrow ependymal lined channel that extends from the fourth ventricle through the length of the spinal cord within the midline of the transverse gray commissure (lamina X of Rexed). It is usually not patent beyon d the 20th year of life.
very center of the spinal cord, so named because it starts as a hollow tube which closes in most people as they age
A small tubular cavity in the center of the spinal cord which is normally not dilated.