Details of Respiratory Membrane, Diffusing Capacity, Respiratory Exchange Ratio as well as Respiratory Quotient

An exchange of respiratory gases occurs between the alveoli and the blood. An exchange of respiratory gases also happens through respiratory membrane. The diffusion capacity is manifested as the volume of gas that diffuses through the respiratory membrane each minute for a pressure gradient. The diffusion capacity is influenced by molecular weight of the gas, pressure gradient, and solubility of gas in fluid medium, thickness of respiratory membrane and total surface area of respiratory membrane. Diffusion of oxygen takes place from atmospheric air into alveoli and from alveoli into blood. Simultaneously diffusion of carbon dioxide happens from blood into alveoli and from alveoli into the atmospheric air. The respiratory exchange ratio is the ratio between the net output if carbon dioxide from the tissues to the simultaneous net uptake of oxygen by the tissues. Respiratory quotient is the molar ratio of carbon dioxide production to oxygen consumption. It helpful in estimating the utilization of different food stuffs