The lung parenchyma constitutes a network of thin-walled alveoli, which facilitate pulmonary gas exchange, notes the United States National Library of Medicine. This matrix of tiny air sacs encompasses a vast internal surface area, which is essential for efficient exchange of oxygen and carbon dioxide.
Adequate gas exchange depends on three key aspects of lung anatomy: parenchymal structural organization, parenchymal mechanical features and trans-pulmonary stress, which constantly keeps the alveoli open for air flow to occur. This transpulmonary stress, also known as prestress, is produced within the pleural cavity. The actual gas exchange occurs at the alveolar level through diffusion, explains the U.S. Library of Medicine.