Anatomy Intramuscular injection of atropine causes initial bradicardia. The reason for this effective being seen is A Stimulation of medullary vagal centre B Stimulation of vagal ganglia C Blockade of ME receptor and SA nodal cells D Blockade of muscarinic auto receptor on vagal nerve ending 💡 Explanation Intramuscular injection of atropine causes initial bradicardia. The reason for this effective being seen is ✓ Correct Answer: D. Blockade of muscarinic auto receptor on vagal nerve ending