Spinal Nerve Roots
Diagram showing relation of neurons composing the spinal nerve roots with adjacent nervous structures. Labels: S.E., sensory epithelium connected by a sensory neuron with spinal cord; S.M., striated muscle receiving the axon from a motor-cell in the ventral horn of the gray matter in the cord; Sp. F., spinal fibers, medullated, sensory, and the motor, passing to the sympathetic ganglion where they connect with sympathetic neurons; S.F., S.F., non-medullated fibers from the sympathetic neurons passing to the viscera, the axons going to the plain muscle (P.M.), the dendrites to the sensory endings (S.E.).