Changes

==Anatomy==

==Anatomy==

The respiratory system is viewed in two parts: the upper respiratory tract and the lower respiratory tract.

The respiratory system is viewed in two parts: the upper respiratory tract and the lower respiratory tract. The system has built-in methods to prevent harmful substances from entering the lungs:

====Upper Respiratory Tract====

====Upper Respiratory Tract====

====Lower Respiratory Tract====

====Lower Respiratory Tract====

This part of the respiratory tract consists the of the bronchi, bronchioles, and alveoli.  All of these structures are contained within the [[lungs]].  The alveoli are responsible for the gas exchange mentioned above.

This part of the respiratory tract consists the of the bronchi, bronchioles, and alveoli.  All of these structures are contained within the [[lungs]].  The alveoli are responsible for the gas exchange mentioned above.

==Physiology==

==Physiology==