Question 3:

Joseph Wong, aged 69-year-old, is admitted to hospital with shortness of breath.  He has chronic obstructive pulmonary disease (COPD) due to smoking. He stops breathing when he is given pure oxygen through a nasal tube.

Part A. What is the normal stimulus for breathing and what normally detects this stimulus?

Part B. Why did Joseph stop breathing when he was given pure oxygen through a nasal tube? Explain your reasoning.

Part C. Once Joseph recovers, the doctor assesses his respiratory function. Explain whether Joseph’s minute ventilation or alveolar ventilation will give a better indication of his respiratory function.