Pressure in a pressure chamber was lowered to 400 mm Hg. How will external respiration change in a person sitting in this chamber?

Answer options

1. Depth of respirations will decrease, frequency of respirations will increase
2. Depth and frequency of respirations will decrease
3. Depth and frequency of respirations will increase
4. Respiration will remain unchanged
5. Depth of respirations will increase, frequency of respirations will decrease