This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'A patient presented in emergency with tachycardia,hypehermia,bronchial dilation and constipation.The person is likely to be suffering from overdose of \nSelect and explain. \nA. Atropine, B. organophosphorus compound, C. Mushroom, D. Paracetamol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref:KD Tripathi pharmacology 7th edition (page.no: 114,115) Actions of Muscarinic antagonist (atropine) CNS stimulation CVS: the prominent effect is tachycardia by abbretes refractory period of AV node and facilitate AV conduction Gland; decrease salivary, tracheobronchial and lacrimatory secretion, gastric secretions Smooth muscle: decrease tone and contraction, bronchodilatation, constipation Eye; mydriasis by contraction of longitudinal ciliary muscle Rise in body temperature (hypehermia)', 'role': 'assistant'}]