This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
Rate of impulse generation is maximum in 
Select and explain. 
A. SA node, B. AV node, C. Bundle of His, D. Purkinje system
A: SA node
Answer: A: SA node 
Explanation: SA node is located at the junction of the superior vena cava with the right atriumEven though Av node Bundle can produce impulse rate of impulse production is higher in SA nodeRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:490