二氧化碳(CO_2)是人体醣和脂肪分解代谢的最终产物之一,成人静息状态下,每分钟产生200毫升左右CO_2,约相当于10毫克分子。CO_2几乎全部产生在线粒体内,并经细胞浆,细胞外液进入血液而后经肺呼出。在健康人,单位时间内呼出的CO_2量和体内生成的量保持相等,因之在静息状态下,动 Carbon dioxide (CO 2) is one of the end products of the body’s sugar and fat catabolism. At rest, adults generate about 200 ml of CO 2 per minute, which is equivalent to about 10 milligrams. Almost all of CO 2 is produced in the mitochondria, and then enters the blood via the cytoplasm and extracellular fluid and exhales through the lungs. In healthy people, the amount of CO 2 exhaled within a unit of time and the amount produced in the body remain the same, so that at rest, moving