Part a
A number of parameters of lung function vary between the upper and the lower part of the lung due to different characteristics pertaining to each part. The upper part of the lung comprises of a compliant, collapsible tube. This implies that it has the ability to tolerate suction pressure that is developed due to rhythmic contraction of the diaphragm which plays a role of sucking air into the lungs. The lower part of the lung on the other hand is a vital system that is depended upon by other body organs including the brain. This implies that when the lower part of the lung is affected, all the other vital body organs would also be affected. It is therefore clear that the lower part of the lung is more crucial compared to the upper part. This accounts for the varying parameters between both lung sections.
Part b
The lower part of the lung contributes more oxygen to the blood at resting breathing compared to the upper part of the lung. The main reason for this is because the lower respiratory tract serves the function of receiving oxygen and distributing it to other parts of the body. Moreover the brain, which is a chief organ that depends on oxygen, is dependent on the lower part of the lungs. Other organs are deprived of oxygen, and shut down in cases when the lower respiratory tract shuts down. This justifies the fact that the lower part of the lung contributes more oxygen compared to the upper part.
