Simple lining epithelial tissue lines much of the respiratory track, including the lungs and the lower airways. A small portion of the respiratory epithelial tissue located in the upper airways is stratified lining epithelial tissue instead of simple.
Simple lining epithelial tissue consists of only one layer. In addition to major portions of the respiratory track, this type of epithelial tissue lines the blood vessels and many glands. Stratified lining epithelial tissue has many layers and lines areas that are more susceptible to damage, such as the upper airways and the digestive track. A third type of epithelial tissue, glandular, forms glands and is not found in organ linings.