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.
Gas Exchange. Gas exchange refers to the passing of Oxygen from the alveoli into the blood flow and the excess Carbon Dioxide (CO2) within the blood flow passing back into the alveoli to be breathed out. Each tiny alveoli is covered in a network of capillaries (tiny blood vessels) which make this process easier.