In: Anatomy and Physiology
Which of the following is true about ventilation-perfusion coupling?
in alveoli where ventilation is inadequate, the partial pressure of oxygen is high
terminal arterioles dilate in areas where the partial pressure of oxygen is low
blood is shifted towards alveoli with low partial pressure of oxygen to enhance oxygen pick-up from lungs
in alveoli where ventilation is maximal, the partial pressure of oxygen is low
terminal arterioles dilate in areas where the partial pressure of oxygen is high
Ans:- b) terminal arterioles dilate in a area where partial pressure of oxygen is low.
so that more income air goes to that area of lung and partial pressure of oxygen increases in that area.
Option A is wrong because ventilation means in flow of air and if in flow of air is magnetic field then automatically partial pressure of Oxygen will be low not high.
Option C :- is wrong is wrong because it blood will be shifted to the elderly where oxygen is already low then less oxygen exchange will take place Tu blood
Similarly option d is wrong because if ventilation will maximum then there will come to lungs so partial pressure of oxygen should be high now coming