Why does diffusion occur more easily through simple squamous epithelium as compared to stratify squamous or columnar epithelia?
Simple squamous epithelium forms the alveolar walls in the lungs and the walls of the capillaries.
Animals contain four basic types of tissues: nervous, connective, muscle, and epithelial. Epithelial tissues are used for lining surfaces, such as the surfaces of body cavities and glands. There are several types of epithelial cells. Epithelial linings that are only one cell thick are called simple while linings that are two or more cells thick are called stratified. And they are also named for the shape of the different cells. Simple type cells are flat, cuboidal type cells are cube shaped, and columnar type cells are tall and thin. So simple squamous epithelial linings are the thinnest type of epithelial linings. This is why they are used for capillaries and lungs. The thinness of the cell coupled with the fact that they are only one cell thick makes it easier for gases to diffuse through the cell lining.