Healthy and fibrotic lung tissue (IMAGE) University of Zurich Caption Healthy lung tissue contains many air-filled alveoli, in which oxygen is absorbed from the respiratory air into the blood (left). In fibrotic lung tissue, these have been displaced by connective tissue growths (right). Credit Christian Stockmann, University of Zurich Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.