key term - Simple squamous epithelium

Definition

Simple squamous epithelium is a single layer of flat, scale-like cells that line surfaces where passive diffusion of gases and fluids occurs. It is found in areas such as the lining of blood vessels (endothelium) and the air sacs of lungs (alveoli).

Related terms

Diffusion:

The process by which molecules move from an area of higher concentration to an area of lower concentration.

Endothelium:

The specialized simple squamous epithelial layer that lines the interior surface of blood vessels.

Alveoli:

Tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place