This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
True regarding respiratory centre 
Select and explain. 
A. Directly simulated by fall in PaO2, B. Connected with cardiac center, C. Inhibited during swallowing, D. Situated in midbrain
B: Connected with cardiac center
Answer: B: Connected with cardiac center 
Explanation: The respiratory center is located in the medulla oblongata and is involved in the minute-to-minute control of breathing. Unlike the cardiac system, respiratory rhythm is not produced by a homogeneous population of pacemaker cells Ref: guyton and hall textbook of medical physiology 12 edition page number: 371,372,373