Changes

<center>For lessons on the [[topic]] of '''''[[Breath]]''''', follow [http://nordan.daynal.org/wiki/index.php?title=Category:Breath this link].</center>

<center>For lessons on the [[topic]] of '''''[[Breath]]''''', follow [http://nordan.daynal.org/wiki/index.php?title=Category:Breath this link].</center>

==Gas exchange==

==Gas exchange==

Breathing is only part of the processes of delivering [[oxygen]] to where it is needed in the body and removing [[carbon dioxide]] waste. The process of [[gas exchange]] occurs in the alveoli by passive diffusion of gases between the alveolar gas and the blood passing by in the lung capillaries. Once in the blood the [[heart]] powers the flow of dissolved gases around the body in the circulation.  

Breathing is only part of the processes of delivering [[oxygen]] to where it is needed in the body and removing [[carbon dioxide]] waste. The process of [[gas exchange]] occurs in the alveoli by passive diffusion of gases between the alveolar gas and the blood passing by in the lung capillaries. Once in the blood the [[heart]] powers the flow of dissolved gases around the body in the circulation.