Automatic movements of the gastrointestinal canal are regulated by the central nervous system by nerves, motor and inhibitory, which make up two separate groups; for the stomach and small intestines, the vagus nerves are motor, inhibiting n. n. splanchnici superiores, while the colon gets its motor fibers from n. n. erigentes (n. n. pelvici), and retardant from n. n. splanchnici inferiores, i.e., withdrawal of the nerve trunks, which go from the sympathetic borderline trunk to the lower mesenteric node and the post-node continuations of which are n. n. hypogastrici and n. mesentericus inf.