A-The lung parenchyma:
The alveoli secrete a film of fluid, including the surfactant, which has a large mechanical function: Indeed, by capillary action, they prevent the cells collapses at the end. At the epithelium, there are several types of cells pneumocytaires and macrocytic. The interstitium it is made up of cells and fibers with role structure.
The parenchyma has many functions: This is where we place the gas exchange, the destruction of certain molecules, their conversion (eg, angiotensin in angiotensinogen by the enzyme conversion) and a role Immune presence in number of alveolar macrophages.
There are two blood circulation in the lungs: the first is provided by the bronchial vessels (arteries and veins, bronchial) and provide the organ of oxygen and substances necessary for its operation. The second, consisting of veins and pulmonary arteries serves the function of gas exchange. (more…)