Molecular Classification
Anatomical Structure, Barrier
Other Names
Blood-Air Barrier, Air-Blood Barrier
Disease Roles
Acute Lung Injury (ALI)Acute Respiratory Distress Syndrome (ARDS)Pulmonary Fibrosis

Alveolar-Capillary Barrier Overview

The alveolar-capillary barrier is a multi-layered structure in the lungs that facilitates gas exchange between inhaled air and the bloodstream. It is composed of the alveolar lining layer, alveolar epithelium (type I and type II pneumocytes), basement membrane, and capillary endothelium. Its primary function is the rapid bidirectional diffusion of oxygen and carbon dioxide. Disruption of this barrier impairs gas exchange, contributing to various lung diseases.

Mechanism of Action

Biological Functions

Gas Exchange
Diffusion
Prevention of Air Embolism
Prevention of Blood Leakage into Alveoli

Disease Associations

Acute Lung Injury (ALI)
Acute Respiratory Distress Syndrome (ARDS)
Pulmonary Fibrosis
Pulmonary Edema
Barotrauma
Interstitial Lung Diseases

Safety Considerations

  • Arterial Gas Embolism (if ruptured)
  • Hemoptysis (if ruptured)
  • Impaired Gas Exchange