Smooth muscle stimulating substances in the intestinal wall.
D000109:Acetylcholine / Q000502:physiology*; D001669:Biochemical Phenomena; D007422:Intestines / Q000502:physiology*; D009130:Muscle, Smooth; D009132:Muscles / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D000109:Acetylcholine
ACETYLCHOLINE/physiology; INTESTINES/physiology; MUSCLES/physiology; SEROTONIN/metabolism