Your spine is made up of 33 vertebrae. Between your vertebrae is a kidney shaped intervertebral disc. These allow for motion of your spine and serve as shock absorbers. A healthy intervertebral disc is comprised of 80% water. There are two main components to a disc. The outer fibrous ring is called the annulus fibrosus and contains layers of fibrocartilage and collagen. The inner portion of the disc is called the nucleus pulposus and is made of loose fibers in a mucoprotein gel. It is gel-like and has an appearance similar to crab meat. When an object is lifted, the force is transmitted directly thru the center of the disc and then redistributed radially to the outer fibrous rings. The outer rings help to resist deformation. It is this combination that enables the disc to act like a shock absorber.