Introductory Anatomy, Histology, and Cell Biology of the Lung

Abstract

The lung predominantly functions as a gas exchange unit between air and blood. Air and blood reach the gas exchange region via parallel conduction pathways. The tissues that form these units must also themselves be suppLied with nutrients and oxygen. There has to be regulation of both blood flow and airflow into the exchange region in order to respond to changes in demand, which is accompLished via neural and locally acting reflexes. Finally, given the environmental exposure of the lung via the airways, there has to be a protective mechanism against harmful agents, including particulates, oxidants, and microorganisms. In order to accompLish this, the lung's major anatomical components are the airway, including the conducting airways and the alveoLi; the vasculature, including both pulmonary and systemic circulations; the interstitium, including all supporting tissues, smooth muscles, and nerves; and finally the hematopoietic elements that provide host defense.