Final answer:
Henry's Law predicts that oxygen (O2) moves from the alveoli, where its partial pressure is high, to the blood in the pulmonary capillaries, where the partial pressure is lower, promoting gas exchange based on pressure gradients and O2 solubility.
Step-by-step explanation:
Understanding Henry's Law in Alveolar Gas Exchange
Henry's Law predicts the movement of O2 during alveolar gas exchange based on the principles that the concentration of O2 dissolved in the blood is directly proportional to the O2's solubility and its partial pressure.
When the partial pressure of O2 in the alveoli is high, more O2 dissolves in the blood due to the gas moving from a region of higher pressure to lower pressure until equilibrium is reached. This is critical in our lungs, where O2 must pass from the air in the alveoli into the blood, and CO2 must move in the opposite direction.
Nitrogen, despite being plentiful in the atmosphere, dissolves less in blood due to its low solubility, highlighting how both solubility and partial pressure contribute to gas transfer.
Gases will always move down their pressure gradient, which in the case of respiration, means from the alveoli (high pressure) to the blood (low pressure) for O2, and from the blood (high pressure) to the alveoli (low pressure) for CO2. This differential in partial pressure drives the diffusion process across the respiratory membrane.