Lung as a mirror in non-pulmonary and systemic disease

Pulmonary manifestations of non-pulmonary and systemic diseases remain very intriguing group of pathological conditions. Lung as a specific organ mirrors the effects of numerous diseases, non-pulmonary and systemic.Part of the answer why so many pathological extrapulmonary events affect the lung is its position against the circulation, where the lungs are, along with the heart, the only organ receiving the total blood volume.Also, the air, while breathing, connects the lung with the environment, so all the blood volume and thousands of liters of air, in some instances polluted and infected, gets into the lungs each day, with each breath, and with each stroke of the heart. So, the two important pipelines of the body meet in the lungs and bring possible pathogenic agents, or just spread the pathological causative agents that affect other organs. The respiratory functions of the lungs are quite familiar to every physician. It has been ascertained that the lungs participate in the metabolism of vasoactive substances, chylomicrons, fatty acids (removing fat from the bloodstream and storing it), storing and metabolizing of glycogen, some drugs, in filtering and degradation of small thrombi, dissolving the bubbles of air, and some other activities. Some of these non-respiratory functions include, serving as a physical layer of soft, shock-absorbent protecting function to the heart. vascular endothelium in other organs. But, The axis guts-liver-lungs acts, along with the circulation, as other determinant of metabolic events, especially when the function of the liver is damaged, and metabolites enter the lungs unchanged, without the liver intervention, or when drugs or other substances are metabolized by the liver „unprepared „ for substances unknown. It also applies to some extent to the drugs administered intravenously. It is also to note that all the lymph from splanchnic organs via lymphatic vessels enters together with venous blood into the lungs. The anatomy of the lungs, its position within the circulation and the non respiratory functions, makes the lung an interesting organ as the site and mirror of extrapulmonary and systemic diseases.