The Respiratory System

Here you will learn about the respiratory system. This system involves your breathing. Your body breathes in oxygen and breathes out carbon dioxide. This is called respiration.* The process of breathing starts at the nostrils. The air goes into the nostrils and into your nose where it gets filtered and warmed. Little hairs in your nose called cilia filter out the dust from the air. Air can also be breathed in by the mouth. After the air has gone through your nose, The air goes to the pharynx, which is at the back of your throat. There is two sides of the pharynx. One is for food (esophagas), and one is for air. The one for air is called the trachea. As the air goes down the trachea, little hairs inside sweep away the particles and fluids out so they don't get into the lungs. The trachea splits into two parts each one going into one of the lungs. In the lungs the trachea splits up even more. There are branches on the trachea inside the lungs. On the ends of each branch are tiny air sacs called the alveoli. The oxygen travels through these tiny air sacs to get to the actual air sacs. The oxygen goes into the bloodstream. Meanwhile, the carbon dioxide moves from the bloodstream to the air sacs and from there, gets breathed out.

*Did you know that a person breathes about 20,000 times a day?

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