what is found in the central canal of the spinal cord
Central canal Throughout the cervical and thoracic regions the central canal is situated in the anterior third of the spinal cord; in the lumbar enlargement it is near the middle, and in the conus medullaris it approaches the posterior surface. It is filled with cerebrospinal fluid, and lined by ciliated, columnar epithelium, outside of which is an encircling band of gelatinous substance, the substantia gelatinosa centralis (or central gelatinous substance of spinal cord). This gelatinous substance consists mainly of neuroglia, but contains a few nerve cells and fibers; it is traversed by processes from the deep ends of the columnar ciliated cells which line the central canal.
Spinal cord The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone where it passes through the foramen magnum, and meets and enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around 45 cm (18 in) in men and around 43 cm (17 in) long in women. Also, the spinal cord has a varying width, ranging from 13 mm (1⁄2 in) thick in the cervical and lumbar regions to 6.4 mm (1⁄4 in) thick in the thoracic area.