CHAPTER 13 SPINAL CORD NERVES AND REFLEXES

gray matter

central butterfly-shaped region of the spinal cord; contains neuronal cell bodies, dendrites, and synapses.

white matter

surrounds spinal gray matter; contains axons organized into ascending and descending tracts.

dorsal horn

receives and processes sensory information entering the spinal cord.

ventral horn

contains somatic motor neuron cell bodies that send output to skeletal muscle.

dorsal root

carries sensory input toward the spinal cord.

dorsal root ganglion

contains cell bodies of sensory neurons.

ventral root

carries motor output away from the spinal cord.

spinal nerve

forms where dorsal and ventral roots join; normally contains both sensory and motor axons.

ascending tracts

carry sensory information toward the brain

descending tracts

carry motor commands from the brain toward spinal cord circuits