Spinal cord: The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain (the medulla oblongata specifically). The spinal cord begins at the occipital bone and extends down to the space between the first and second lumbar vertebrae. Based on its location, spinal cord is divided into different segments including cervical, thoracic, lumbar, sacral and coccygeal segments. The spinal cord functions primarily in the transmission of neural signals between the brain and the rest of the body but also contains neural circuits that can independently control numerous reflexes and central pattern generators. The spinal cord has three major functions: as a conduit for motor information, which travels down the spinal cord, as a conduit for sensory information in the reverse direction, and finally as a center for coordinating certain reflexes.