Gas exchange is a process in biology where gases contained in an organism and atmosphere transfer or exchange. In human gas-exchange, gases contained in the blood of human bodies exchange with gases contained in the atmosphere. Human gas-exchange occurs in the lungs. In unicellular organisms the respiratory surface and gas-exchange is governed by Fick's law. In humans and mammals, respiratory gas exchange is carried out by mechanisms of the heart and lungs. Ventilation is the process of air movement into and out of the lungs. Once air enters the lungs, diffusion of O2 and CO2 occurs in the alveoli. The oxygenated blood is then perfused throughout the body where gas exchange occurs in the capillary beds.
Read more about Gas Exchange: Pulmonary Physics, Interchange, Diffusion, Control of Respiration
Famous quotes containing the words gas and/or exchange:
“Man moves in all modes, by legs of horses, by wings of winds, by steam, by gas of balloon, by electricity, and stands on tiptoe threatening to hunt the eagle in his own element.”
—Ralph Waldo Emerson (1803–1882)
“To coöperate in the highest as well as the lowest sense, means to get our living together. I heard it proposed lately that two young men should travel together over the world, the one without money, earning his means as he went, before the mast and behind the plow, the other carrying a bill of exchange in his pocket. It was easy to see that they could not long be companions or coöperate, since one would not operate at all. They would part at the first interesting crisis in their adventures.”
—Henry David Thoreau (1817–1862)