Lung - distributing and respiratory airways (10x objective lens)


This composite image from two micrographs shows a longitudinal section through an airway in a lung from a mouse. At the upper end the airway is a segmental bronchus (tertiary bronchus), as shown by the presence of cartilage in the wall. Where the cartilage plates end marks the beginning of a bronchiole, which, almost immediately, becomes a respiratory bronchiole, which has a wall that is partially conducting, like a bronchiole, and partially respiratory. This transition marks the beginning of the respiratory area of the lung. The passage then becomes an alveolar duct, which leads, in turn, to numerous alveoli. Note: Owing to the collapse of the alveoli during fixation, the structure of the respiratory areas is not as clear as in a preparation fixed with the lungs inflated.
Stain = Iron Hematoxylin

Go to higher magnification Go to higher magnification of a respiratory bronchiole in cross section Return to Respiratory System. Return to the Table of Contents.


Copyright Paul B. Bell, Jr. & Barbara Safiejko-Mroczka

The University of Oklahoma

Version 010603