Wikijunior:Biology/Systems/Respiratory System

Lungs

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. Cells make carbon dioxide which can poison our bodies. Our lungs push this out of our bodies.

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

Parts of the respiratory system are the nose, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

• Air comes in through the nostrils and mouth.
• Dust is removed by the hair in the nose.
• Air goes through the pharynx (in the back of the mouth), 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 air sacs called alveoli.
• This is where the oxygen goes into the blood and carbon dioxide comes out.