Question

Air

Answer 1

Answer:

All animals need oxygen to make energy from food. We get this oxygen from the air that we breathe. In order to get the oxygen into the blood where it can be transported to the rest of the body, the air travels through a system of organs called the respiratory system. When you inhale, air enters the body through the nose or the mouth. From there it passes through the pharynx, which forces air into the trachea and food into the esophagus. The air travels down the trachea into two branching tubes called bronchi and then on into the lungs. In the lungs oxygen from the air enters the blood. At the same time, the waste gas carbon dioxide leaves the blood and then leaves the body when you exhale. Some water vapor also leaves the body when you exhale, which is why mirrors get foggy when you breathe on them. The diaphragm is the muscle that controls the lungs. It is important to keep the respiratory system clear so oxygen can keep flowing into your body. If something gets in your nose and irritates it, you sneeze. If something gets in your trachea or bronchi and irritates it, you cough. If something irritates your diaphragm, you hiccup. Finally, if the brain thinks you are not getting enough oxygen, then it forces you to yawn.

 

-TheUnknownScientist 72