Human Lung Diagram

Human Lung Diagram The lungs are located in the thoracic chamber which is an air tight chamber which is formed dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and on the lower side by the dome shaped diaphragm. Lungs are paired soft, spongy organ responsible for gas exchange between the atmosphere and the blood. Inhaled oxygen is supplied to the blood and carbon dioxide is removed from the blood and is exhaled out. Each of the lungs is s divided into lobes. The left lung has two lobes and the right has three lobes. The lobed lungs are enclosed in a double layered membrane called the Pleura. This membrane allows the lungs to move against the ribcage with minimal friction. Lying between two lungs is the mediastinum containing the heart, esophagus, trachea and major vessels and nerves. The positioning of these organs result in the left lung being smaller than the right, as the heart and its associated vessels require more space in the left side of the chest. The branching network of bronchi, bronchioles, and alveoli constitute the lungs. Each of the two bronchi branches into secondary or lobar bronchi then into smaller bronchiole. The bronchioles end at the alveolus. The total number of alveoli in both lungs is estimated as 300 million. So the total alveolar surface, available for gas exchange far exceeds the general body surface. In adult man, the surface area of skin is around 1.6 m2 only, but the total alveolar space is nearly 100 m2.The bronchi are strengthened by cartilage while the bronchioles are entirely muscular.