Roots of Spinal Nerves
Illustrating the functions of the roots of the spinal nerves. Labels: a, ventral root; p, dorsal root. Divided at a. -- Irritated at 1: no result. Irritated at 2: contraction of muscles supplied with fibers from the root. Divided at p. -- Irritated at 3: no result. Irritated at 4: pain produced.