Alvarado Alcibey, Arce Isabel
Internal Medicine and Neumology, Clinica de Diagnostico Medico, San Jose, Costa Rica.
Medicine and General Surgery, Medicine School, University of Costa Rica, San Jose, Costa Rica.
J Clin Med Res. 2016 Oct;8(10):689-700. doi: 10.14740/jocmr2668w. Epub 2016 Aug 30.
The primary function of the lungs is gas exchange. Approximately 400 million years ago, the Earth's atmosphere gained enough oxygen in the gas phase for the animals that emerged from the sea to breathe air. The first lungs were merely primitive air sacs with a few vessels in the walls that served as accessory organs of gas exchange to supplement the gills. Eons later, as animals grew accustomed to a solely terrestrial life, the lungs became highly compartmentalized to provide the vast air-blood surface necessary for O2 uptake and CO2 elimination, and a respiratory control system was developed to regulate breathing in accordance with metabolic demands and other needs. With the evolution and phylogenetic development, lungs were taking a variety of other specialized functions to maintain homeostasis, which we will call the non-respiratory functions of the lung and that often, and by mistake, are believed to have little or no connection with the replacement gas. In this review, we focus on the metabolic functions of the lung, perhaps the least known, and mainly, in the lipid metabolism and blood-adult lung vascular endothelium interaction. When these functions are altered, respiratory disorders or diseases appear, which are discussed concisely, emphasizing how they impact the most important function of the lungs: external respiration.
肺的主要功能是气体交换。大约4亿年前，地球大气中的气相氧气含量增加，使得从海洋中出现的动物能够呼吸空气。最初的肺仅仅是原始的气囊，其壁上有一些血管，作为气体交换的辅助器官来补充鳃的功能。经过漫长的岁月，随着动物逐渐适应完全的陆地生活，肺变得高度分隔化，以提供摄取氧气和排出二氧化碳所需的巨大气血表面，并且发展出了一个呼吸控制系统，根据代谢需求和其他需要来调节呼吸。随着进化和系统发育的发展，肺承担了多种其他特殊功能以维持体内平衡，我们将其称为肺的非呼吸功能，而这些功能常常被错误地认为与气体交换几乎没有或没有关联。在这篇综述中，我们聚焦于肺的代谢功能，这可能是最不为人所知的，主要涉及脂质代谢以及血液与成年肺血管内皮的相互作用。当这些功能发生改变时，就会出现呼吸紊乱或疾病，我们将简要讨论这些情况，重点强调它们如何影响肺的最重要功能：外呼吸。
