What Are The Breathing Organs In Human Body?
The two lungs, which are lobed, are spongy elastic organs filling up most of the chest cavity. They look solid, but in reality consist of a mass of tubes called bronchioles. These tubes branch repeatedly and become finer and finer until they end up as blind-ending alveoli. It is these millions of alveoli that provide enormous surface area for gaseous exchange. The lungs are in direct contact with the atmosphere through the nostrils, nasal cavity, larynx, trachea (wind pipe) and the two bronchi. Each lung is enclosed by two transparent membranes, the pleurae. The inner one covers the lung itself and the outer one is attached to the chest wall. The chest cavity is air tight and separated from the abdomen by a dome-shaped structure, the diaphragm. The sternum, ribs and backbone, together with muscles of the chest wall, provide a tough box which surround the lungs and heart and afford them essential protection.
