Buna is a census-designated place in Jasper County, Texas, United States. The population was 2,142 at the 2010 census.
Gas Exchange. Gas exchange is the process by which oxygen and carbon dioxide (the respiratory gases) move in opposite directions across an organism's respiratory membranes, between the air or water of the external environment and the body fluids of the internal environment.
Alveolar dead space is the part of the inspired gas which passes through the anatomical dead space to mix with gas at the alveolar level, but does not participate in gas exchange. (i.e. infinite V/Q).