TORONTO -. Mike Babcock's first exhibition schedule as coach of the Maple Leafs will take him to some interesting arenas.
There are two types of 'respiration': pulmonary (visible breathing) and cellular (which is not visible). In pulmonary respiration the unwanted gas expelled is mainly carbon dioxide. This is then replaced during the inhalation breathing phase by the oxygen content in the air.
Respiration means the release of energy from food. This is a process carried out by all living things. The chemical process involved works most efficiently if oxygen is used. Just like a fire needs an oxygen supply to burn the fuel, so aerobic respiration needs oxygen.