Wikijunior:Biology/Systems/Respiratory System

The Respiratory System
The respiratory system is how air gets into our bodies. We breathe in and out with our lungs. The air we breathe in has something called oxygen that our cells need to work. The cells take in the oxygen and make an element called carbon dioxide, which we then breathe out.

The respiratory system works together with the circulatory system to make sure that oxygen gets to each cell of the body.

Some parts of the respiratory system are the nose, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli. Here is how they all work together:


 * Air comes in through the nostrils and mouth.
 * Dust is removed by the hair in the nose.
 * Air goes through the pharynx (which is found in the back of the mouth), through the larynx or the voice box, and down the trachea (windpipe).
 * The trachea splits into two major bronchi, one for each lung.
 * This further splits into smaller bronchi, then into smaller tubes called bronchioles which lead into the membranous organ called alveoli.
 * This is where the oxygen goes into the blood and carbon dioxide comes out.