Infections of the Respiratory System

Why is this system important?  The respiratory system is the most commonly infected system  Health care providers will see more respiratory infections than any other type

Overview

The Respiratory System  A major portal of entry for infectious organisms  It is divided into two tracts – upper and lower respiratory tracts  The division is based on structures and functions in each part.  The two parts have different types of infections

Labeling Assignment  Now that you know your respiratory system is divided into 2 parts, the upper and the lower respiratory tracts, label the diagram with the correct components that make up each tract.  Use the following words:  Alveolus  Throat (pharynx)  Bronchus  Lung  Mouth  Larynx  Nasal Cavity  Wind pipe (trachea)  Nose  Bronchiole  After labeling each component draw a line where you believe the upper and lower respiratory tracts

The Respiratory Tract  The Upper Respiratory Tract  Nasal cavity, nose, mouth, pharynx,  Infections are fairly common  Usually nothing more than an irritation  The Lower Respiratory Tract  Larynx, Trachea, Lungs, Bronchus, Bronchiole, Alveolus  Infections are more dangerous  Can be very difficult to treat

Respiratory functions 1.supplies the body with oxygen and disposes of carbon dioxide 2.filters inspired air 3.produces sound 4.contains receptors for smell 5.rids the body of some excess water and heat 6.helps regulate blood pH

Pathogens of the Respiratory System  Respiratory pathogens are easily transmitted from human to human  They circulate within a community  Infections spread easily  sneeze sneeze  Some respiratory pathogens exist as part of the normal flora  Others are acquired from animal source, water, air etc  Fungi are also a source of respiratory infection  Usually in immunocompromised patients

Pathogens of the Respiratory System cont’d  Some pathogens are restricted to certain sites  Legionella only infects the lung  Other pathogens cause infection in multiple sites  Streptococcus can cause:  Middle ear infections  Sinusitis  Pneumonia

Defenses of the Respiratory System  The body has a variety of host defense mechanisms  Innate immune response  the cells and mechanisms that defend the host from infection by other organisms, in a non-specific manner  Adaptive immune  It is adaptive immunity because the body's immune system prepares itself for future challenges

Defenses of the Respiratory System  The respiratory system has significant defenses  The upper respiratory tract has:  Mucociliary escalator  As air usually enters the body through the nose (a preferable point of entry)  Cilia (fine hairs) protect against dust and other particles from the air  Particles that may slip through the cilia are caught in the thick, sticky, mucous lining of the nasal cavity  Air is warmed in the nasal cavity and finally moisture is added  Coughing  Secretory IgA  The lower respiratory tract has:  Alveolar macrophages  IgA

Defenses of the Respiratory System cont’d