Spinal canal refers to the hollow passage formed by the foramen of the vertebrae through which the spinal cord runs. The spinal canal is filled with cerebrospinal fluid that bathes the nerves. The canal originates at the base of the skull and ends at the sacrum. As the spinal cord descends through the canal, nerve roots emerge from holes to each side of the canal and at the end of the spinal cord, nerves branch out forming a horse-like tail. A condition called spinal stenosis results when the nerve root becomes compressed or choked as it exits the spinal canal due to disc herniation or bone spurs.