Spinal Cord

Many important features of the spinal cord are visible in this cross section. The white matter is composed of nerve fibers carrying ascending and descending information and makes up the outer regions of the cord. The gray matter, which contains cell bodies, is located in the center of the cord and is easily identified by its color and butterfly shape. The central canal lies in the center of the cord and contains cerebrospinal fluid. The dorsal root contains afferent sensory fibers that transmit signals from the periphery, through the dorsal root ganglion, to the dorsal horn. The ventral root contains efferent motor axons. The ventral and dorsal roots come together to form a spinal nerve. What classes of neurons have their cell bodies in the dorsal horn and ventral horn? What is the direction of the action potentials for both of these classes?