| > | | | | respiration process of gas exhange can happen |
| The lungs are massive vessel-like organs in the chest | | | | through simple diffusion. In large organisms, however, |
| cavity. They are the largest and most essential part of | | | | this is impossible, because a very small amount of cells |
| the respiration system. The air we breathe enters and | | | | in large organisms are located close enough to the |
| exits our lungs through two passages; the bronchioles | | | | surface for diffusion to take place. Two major |
| and the bronchi. Lungs' main responsibilty is to take | | | | changes made it possible for all organisms to attain |
| oxygen from the atmosphere and transport it into the | | | | multicellularity. One being an efficient circulatory system |
| bloodstreem. It then excretes carbon dioxide from | | | | to transport gases to and from all tissues in the body. |
| blood into the atmoshpere. This gas exchange | | | | The other is a large respiratory system. The |
| happens through specialized cells that form many | | | | respiratory system centralizes the responsibilty of |
| millions of thin-walled air sacs. Some non-respiratory | | | | collecting oxygen from the atmosphere and brings it |
| functions are also performed by the lungs. The lungs | | | | into the body, where it can be rapidly sent to tissues |
| are massive vessel-like organs in the chest cavity. | | | | through the circulatory system. |
| They are the largest and most essential part of the | | | | Lungs also have several jobs that do not include the |
| respiration system. The air we breathe enters and | | | | respiratory function. A main job for the lungs is to |
| exits our lungs through two passages; the bronchioles | | | | protect the heart. They surround the heart and act as |
| and the bronchi. Lungs' main responsibilty is to take | | | | cushions to soften any blow that the heart may have |
| oxygen from the atmosphere and transport it into the | | | | to endure. Without this padding, simply bumping into |
| bloodstreem. It then excretes carbon dioxide from | | | | someone could be fatal. Another responsibilty of this |
| blood into the atmoshpere. This gas exchange | | | | organ is to influence the concentration of biologically |
| happens through specialized cells that form many | | | | active drugs and other substances which are used in |
| millions of thin-walled air sacs. Some non-respiratory | | | | medicine. Filtering out small blood clots formed in the |
| functions are also performed by the lungs. | | | | systemic veins is another task performed by the lungs. |
| In single celled bacteria and other small organisms, the | | | | |