respiratorysystem Mr. Schmidt
Summit Career College
The Respiratory System

The respiratory system comprises those organs which are concerned with the exchange of gases between the organism and its environment, specifically the intake of oxygen and the discharge of carbon dioxide. The exchange of gases between the blood and the air taken into the lungs is external respiration; the exchange of gases between the circulatory fluids (blood, lymph, tissue fluid) and the cells is referred to as internal respiration.
Accessory functions that are associated with the respiration or accomplished with the aid of respiratory organs are: (1) production of sound; (2) elimination of volatile waste substances, such as water and acetone, (3) elimination of excess heat from the body.


The upper structures of the respsiratory system are combined with the sensory organs of smell and taste (in the nasal cavity and the mouth) and the digestive system (from the oral cavity to the pharynx). At the pharynx, the specialized respiratory organs diverge into the airway. the larynx, or voicebox, is located at the head of the trachea, or windpipe. The trachea extends down to the bronchi which branch off at the trachial bifurcation to enter the hilus of the left or right lung. The lungs contain the narrower passageways, or bronchioles, which carry air to the chambers, oxygen is transferred through the membrane of the alveolar walls to the blood cells in the capillaries within. Likewise, waste gases diffuseout of the blood cells into the air in the alveoli, to be expelled upon exhalation. The diaphragm, a large, thin muscle below the lungs, and the intercostal and abdominal muscles are responsible for contracting and expanding the thoracic cavity to effect respiration. The ribs serve as a structural support for the whole thoracic arrangement, and pleural membranes help provide lubrication for the respiratory organs so that they are not chafed during respiration.
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Last updated  2008/09/28 05:18:04 PDTHits  406