Germs can live in the respiratory system

The respiratory system consists of the upper airway, including the nose, throat, and windpipe, and the lower airway, including the lungs. Many germs live in the upper airway. Like the skin and digestive system, most germs commonly found in the nose, mouth, and throat keep those parts of the body healthy. However, some germs may be there because someone has an infection. Germs in the nose and mouth can be easily spread to the skin and hands when you touch your face. From there, germs can spread to surfaces and other people who may become infected. The defenses of the nose, mouth, and throat keep a lot of germs from getting into the lungs. When germs do get into the lungs, the lungs have defenses for getting germs out, like coughing.