Your Lungs

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The Respiratory System Definitions:    1.  The NOSE is the specialized structure that serves as an organ of the sense of smell, and as part of the respiratory system, acting as a filter and warmer of inspired air.                                     10. The RIGHT LUNG is one of a pair of organs that are responsible for respiration.  The right lung is slightly larger and has three lobes (sections): upper, middle, and lower.  2.  The MOUTH is another entrance for inspired air.  However, air inhaled this way is not conditioned as it is through the nose.   11. The LEFT LUNG is also responsible for respiration.  It is separated from the right lung by the heart and is slightly smaller.  The left lung has two lobes (sections): upper and lower. 3.  The PHARYNX (throat) is the area between the mouth and the nose and the esophagus.  The NASOPHARYNX is the space above the soft palate to the interior of the nose. 12-13. The RIGHT and LEFT MAIN BRONCHI split from the trachea.  They branch out to each lobe and continue branching to the smallest of airways - the bronchioles.  Note: The bronchial tubes are lined with CILIA, microscopic hairs that beat continuously.  Their sweeping motion carries a thin layer of MUCUS (a clear, sticky fluid) that traps dirt, debris, and germs, keeping the lungs clean. 4.  The OROPHARYNX is the area that lies between the soft palate and the upper edge of the epiglottis. 14. The BRONCHIOLES are the smallest branches of the bronchial tubes. 5.  The LARYNGOPHARYNX is another part of the pharynx which lies below the upper edge of the epiglottis and opens into the larynx and esophagus. 15. The PLUERA is a moist, 2-layer membrane which encloses each lung and lines the chest wall. 6.  The EPIGLOTTIS is the lid-like structure which covers the entrance of the trachea.  When closed anything that is swallowed is directed to the esophagus and then to the stomach. 16. The ALVEOLI are microscopic air sacs where gas exchange occurs through the CAPILLARIES, the smallest blood vessels. 7.  The LARYNX or "voice box" contains the vocal chords.  During speech, air moves passed the vocal chords causing vibration and in turn sound.                                         17. The DIAPHRAGM is the major muscle of respiration.  This strong sheet of muscle completely separates the chest cavity from the abdominal cavity.  When this muscle contracts, air fills the lungs and when it relaxes, air is exhaled from the lungs.  8.  The ESOPHAGUS is the passageway from the mouth and throat to the stomach.   9.  The TRACHEA, also known as the "windpipe", leads from the pharynx to the lungs. Note: Although the RIBS are not depicted, they are bony structures that define and support the chest cavity and provide protection to the lungs.              Click HERE for a copy of the diagram and its definitions.