This image shows a cross section of a terminal bronchiole.  Within the lung, tertiary bronchi become progressively smaller and eventually form small airways called terminal bronchioles.  Note that this  bronchiole is lined with a thick layer of ciliated columnar epithelium whose cilia help to remove  foreign debris from the lungs.   A thin (but complete) layer of smooth muscle that can regulate  the diameter of the bronchiole can also be seen. 

This site was last modified May 10, 2002.    NOTE: These pages are best viewed at a screen size of 800 X 600 pixels.

The address of A/P Lab is:  http://bioweb.uwlax.edu/aplab/      Direct comments or questions to gillis.rick@uwlax.edu