Quick Review
The primary function of the lungs is to move O2 into the blood and remove CO2 from the blood.
The contraction and relaxation of the diaphragm draws air through the upper respiratory tract and the bronchi into the bronchioles down into the alveoli.
The lungs have 2 separate circulations.
The Bronchial Circulation provides blood supply to the lung tissues, while the Pulmonary Circulation takes part in gas exchange.
Capillaries surrounding the alveoli receive deoxygenated blood from the pulmonary arteries and deliver oxygenated blood to the pulmonary veins.
Both perfusion and ventilation are necessary for gas exchange to take place.
Hypoxic Pulmonary Vasoconstriction = If the ventilation of alveoli decreases, the pulmonary arteries vasoconstrict to reduce the perfusion to those alveoli and divert blood to better ventilated areas.
