Nerve formed by the union of the sensory and motor roots; it communicates nerve messages between the spinal cord and the various parts of the organism.
meninges
Each of three fibrous membranes surrounding and protecting the central nervous system (spinal cord, encephalon).
dura mater
Thick and resistant outer meninx fusing with the tissue covering the spinal nerves; it does not adhere directly to the bony vertebral wall.
white matter
Section of the spinal cord made up of nerve fibers (axons) and surrounding the gray matter.
arachnoid
Meninx located between the dura mater and the pia mater.
anterior horn
Each of the terminal parts of two masses of gray matter enclosing the cell bodies of motor neurons and from which the motor root originates.
gray matter
Central part of the spinal cord primarily made of the cell bodies of neurons.
posterior horn
Each of the terminal parts of the two masses of gray matter enclosing the associative neurons through which the sensory root enters the spinal cord.
spinal ganglion
Bulge of the posterior sensory root of the spinal nerve; it encloses the cell bodies of the neuron sensors.
sensitive root
Bundle of sensory nerve fibers (axons) communicating information from the periphery of the body to the spinal cord.
motor root
Bundle of motor nerve fibers (axons) communicating information from the spinal cord to the periphery of the body, especially the muscles.
