D) vagus (X) nerves. The smooth muscle of the digestive viscera is served largely by the vagus (X) nerves. It is responsible for parasympathetic output to visceral organs, especially the intestines (responsible for gastrointestinal peristalsis). It carries some motor information back to the organs. The solitary nucleus receives primary afferents from visceral organs. We can also say that the smooth muscle of the digestive viscera is served largely by the tenth cranial nerve.
