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The Respiratory System

Ask yourself…  Yes No
Do you frequently sneeze when seasons change?    
Do you smoke?    
Do you have genetic diseases such as asthma?    
Do you snore?    
Do you often have difficulty breathing?    
Do you live in the city?    
Do you often have phlegm in your throat?    
Do you often suffer from a persistent cough?    
Do you often suffer from a blocked nose?    


Though it may look simple, the act of breathing is one of the most essential activities of the body.  At the same time, it is the function that is most often responsible for pathogens to enter our body.  We are fortunate, however, that the respiratory system is well equipped to prevent these pathogens from reaching the lungs.  

The respiratory tract is composed of the nose, throat, trachea and bronchial tubes.  This set up makes it difficult for invaders to reach the lungs. For example, the curving nasal passage creates a shifting air stream that hinders invaders from entering the respiratory tract.  The mucous along the nasal cavity is designed to catch and expel invaders from the system.  Invaders who still manage to bypass these defenses must deal with the tonsils and adenoids, which trap and destroy foreign substances.  Beyond these organs lie the trachea and bronchial tubes that are lined with mucous membranes to catch more persistent particles.  Trapped particles are then swept out of the respiratory tract by fine, hair-like structures called cilia.  However, these defenses, as intelligent as they may seem, cannot provide complete protection for the body. 

Therein lies the importance of immune cells and associate actions.  Lysozyme is an enzyme found in the mucous of the respiratory tract.  It dissolves the cell walls of bacteria.  The respiratory system also produces antibodies that kill bacteria and viruses.  The alveolar macrophage is an especially powerful immune cell found in the respiratory system.  It stations itself in the lungs and engulfs and destroys substances that find their way past the system's initial defenses.  

The respiratory system's immune function helps to prevent the risk of airborne diseases that we face very day.  Sometimes, this system's mechanisms can malfunction, especially when we do not eat a balanced diet.  One example of a system malfunction is respiratory allergies, which occur when our immune cells mistake a harmless substance for a more dangerous threat.  When the immune system tries to expel these substances from the respiratory tract, we experience symptoms similar to that of the common cold – sore throat, coughing, sneezing and runny nose.