1. The respiratory system is a group of organs that perform some very important tasks in our body.

2. In the mitrochondria of every cell in our body, a process called cellular respiration is carried out. In cellular respiration, (click) glucose, which is carried by the bloodstream (click) reacts with oxygen, also carried by the bloodstream (click) to produce carbon dioxide, which goes into the bloodstream, (click) water, (click) and energy. mitochondrion

3. The three main functions of our respiratory system are to (click) get oxygen to the bloodstream, which carries it to all body cells, (click) remove carbon dioxide from the bloodstream and our body, (click) and remove some of the excess water from the bloodstream and our body. gets oxygen to the bloodstream The Respiratory System removes carbon dioxide from the bloodstream removes some water from the bloodstream

4. Now we’ll show you the main parts of the respiratory system and briefly explain what each of them does. The Respiratory System

5. The air you breathe in with your nose goes into the nasal cavity. Hairs and mucous in the nose trap some particles, and the air is also warmed and moistened. nasal cavity

6. Of course, you can also breathe in air through the mouth or oval cavity. nasal cavity oral cavity

7. Air from both the nasal and oral cavities goes into the pharynx, or throat. pharynx nasal cavity oral cavity

8. The opening at the top of the windpipe, or trachea is called the glottis pharynx nasal cavity glottis oral cavity

9. A flap of tissue called the epiglottis covers the glottis when food is being swallowed. This prevents food from entering the respiratory tract. epiglottis pharynx nasal cavity glottis oral cavity

10. The top part of the trachea is called the larynx. The larynx contains the vocal chords. epiglottis pharynx nasal cavity glottis larynx oral cavity

11. The trachea is the main tube by which air moves from the pharynx to the lungs. The white rings which surround the trachea are made of cartilidge, a tough type of tissue that is a bit softer than bone, but harder than muscle. These rings prevent the trachea from collapsing. epiglottis pharynx trachea glottis larynx nasal cavity oral cavity

12. The trachea branches into two tubes called bronchi. One bronchus goes to each lung. epiglottis pharynx trachea glottis larynx bronchi nasal cavity oral cavity

13. The bronchi branch into many tubes called bronchioles. As they get further from the bronchi, bronchioles get smaller and smaller. Bronchioles carry air to every part of each lung. epiglottis pharynx trachea glottis larynx bronchi bronchioles nasal cavity oral cavity

14. The rib cage surrounds the lungs. These ribs protect the lungs and also play a role in breathing, as we’ll see later. epiglottis pharynx trachea glottis larynx rib cage bronchi bronchioles nasal cavity oral cavity

15. The lungs are the organs in which gas exchange takes place. We have a left lung and a right lung. epiglottis pharynx trachea lung glottis larynx rib cage bronchi bronchioles nasal cavity oral cavity

16. A large, parachute-shaped muscle at the bottom of the chest cavity is called the diaphragm. It separates the chest cavity from the abdominal cavity. The diaphragm plays a very important role in breathing. epiglottis pharynx trachea lung diaphragm glottis larynx rib cage bronchi bronchioles nasal cavity oral cavity

17. Now we’ll take a closer look at ends of the bronchioles. If we take this little blue square…

18. And enlarge it, we’ll represent it by this diagram.

19. These are clusters of tiny air sacs, or aveolar sacs. alveolar sacs

20. Each tiny sac is called an alveolus. It is hollow inside and has a very thin membrane on the outside. Gas exchange between the lungs and the blood occurs through this membrane. The plural of alveolus is alveoli. It has been estimated that each lung contains up to 300 million alveoli. This provides a huge surface area for the gas exchange needed by our body. alveoli alveolar sacs

21. Air enters and leaves the alveoli through the bronchioles. air bronchiolealveoli alveolar sacs

22. A very dense bed of tiny capillaries surrounds each alveolus. This brings blood into very close contact with the outer membranes of alveoli, through which oxygen and carbon dioxide diffuse. air bronchiolealveoli capillaries alveolar sacs

23. The blood vessels coloured blue are carrying deoxygenated blood from the heart. As this blood goes through the capillary beds, it gradually absorbs oxygen from the alveoli and becomes red. air bronchiole deoxygenated blood from the heart alveoli capillaries alveolar sacs

24. These vessels carry red, or oxygenated blood back to the heart. air oxygenated blood to the heart bronchiole deoxygenated blood from the heart alveoli capillaries alveolar sacs

25. Acknowledgements for Images Used "Respiratory system complete en" by LadyofHats - The image i did myself as sources i used the books: Sobotta "atlas der anatomie des menschen" ISBN. 3 541 02828 9, Churchill livingstone "gray's anatomy" ISBN. 0 433 01505 8, Interamericana. McGraw-hill "atlas forografico de anatomia del cuerpo humano" ISBN. 968 25 1677 3. Also used several online diagrams like ([1] and [2]) Image renamed from Image:Respiratory system complete.svg. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Respiratory _system_complete_en.svg#/media/File:Respiratory_ system_complete_en.svg