The enteric nervous system.
D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D004064:Digestive System / Q000294:innervation*; D007421:Intestine, Small / Q000294:innervation; D009197:Myenteric Plexus / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology; D018377:Neurotransmitter Agents / Q000502:physiology; D009638:Norepinephrine / Q000502:physiology; D011950:Receptors, Cholinergic / Q000502:physiology; D012701:Serotonin / Q000502:physiology
D018377:Neurotransmitter Agents; D011950:Receptors, Cholinergic; D012701:Serotonin; D000109:Acetylcholine; D009638:Norepinephrine