Final answer:
The ideal ratio of ventilation and perfusion in the alveolus is 1:1 so that at the end of gas exchange, the capillaries and alveolus have equal partial pressure of O2 and CO2.
Step-by-step explanation:
The ideal ratio of ventilation and perfusion in the alveolus is 1:1 so that at the end of gas exchange, the capillaries and alveolus have equal partial pressure of O2 and CO2.
For efficient gas exchange, the partial pressure of oxygen in the alveoli must be higher than the partial pressure of oxygen in the blood and the partial pressure of carbon dioxide in the alveoli must be lower than the partial pressure of carbon dioxide in the blood. This partial pressure difference allows oxygen to diffuse from the alveoli into the blood and carbon dioxide to diffuse from the blood into the alveoli.
Factors such as ventilation rate and blood flow can influence the ratio of ventilation and perfusion in the alveoli. The body has mechanisms, such as constriction and dilation of blood vessels, to adjust blood flow to alveoli based on their ventilation rate.