This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'Which neurotransmitter is responsible for anterograde dilatation of the small intestine? \nSelect and explain. \nA. image_question, B. image_question, C. image_question, D. image_question', 'role': 'user'}, {'content': 'Answer: A \nExplanation: VIP is responsible for antergrade dilatation of the small intestine. Cholinergic neurons passing inn antegrade direction produce NO and VIP which cause relaxation of a segment of the intestine in front of the bolus. Cholinergic neurons passing in retrograde direction produce substance P and acetylcholine which cause contraction of a segment of the intestine behind the bolus. Ref: Ganong&;s Review of Medical Physiology 26th edition Pgno: 485', 'role': 'assistant'}]