The human respiratory system is a complex system involving the coordination of organs with different structural, functional and defensive mechanisms. The high costs and the high fatality rates associated with chronic respiratory disorders require some serious rethinking in our approach to managing the problem. It transpires that the maxim 'prevention is better than cure' is very apt in the management of respiratory disorders. Smoking is identified as the single most important cause for most of the serious respiratory problems including COPD and lung cancer, and hence abstaining from smoking eliminates the risk for the onset of several serious respiratory disorders.
             The human respiratory system is a well-developed and complex system involving many different organs such as the nasal cavity, pharynx, trachea and the lungs. Though the actual physiological function of breathing begins only at birth, the development of the respiratory tract, the diaphragm and the lungs occur much earlier in the embryonic stage. Structural and functional changes continue from infancy to adulthood and into old age, as the respiratory system matures with age. There are various diseases of the respiratory system such as asthma, tuberculosis, chronic obstructive pulmonary disease (COPD), emphysema, lung cancer, etc. While Asthma is a genetic disease, Tuberculosis, lung cancer, etc, are acquired pulmonary diseases. Life style and environmental factors are important in contributing to and increasing the susceptibility to respiratory disorders. The following discussion includes a brief overview of the structural development of the human respiratory system followed by an overview of COPD and Tuberculosis, two of the prevalent diseases of the respiratory system, and their impact on occupational performance.
             The development of the Respiratory System
             The development of the respiratory system starts after the fourth week of gestation. The respirat...