alveoli
They walls are a single layer of squamous epithelial cells.
A squamous epithelial is an epithelium tissue. It is a flat, scale like cell and can have either a single layer or multiple layers.
The innermost layer of epithelial cells of a blood vessel is called endothelium.
the walls of the alveoli are very thin but strong layers of elastic tissue lines with a single layer of flattened epithelium.
Simple squamous
The cheek epithelial cells are flat and irregularly shaped. They are polygonal squamous cells that have a very thin membrane.
Single layer of Simple Squamous Epithelium
Epithelial tissue exists in stratified and single layers.
The pericardium is the layer of the heart formed by a single sheet of squamous epithelial cells covering connective tissue. It acts as a protective membrane around the heart and prevents friction as the heart beats.
During squamous epithelial cells, the cells are flat and thin, allowing for efficient diffusion and filtration. They line surfaces involved in absorption and secretion, such as the alveoli in the lungs and the lining of blood vessels. Squamous epithelial cells can be simple (single layer) or stratified (multiple layers), depending on their location and function within the body.
Simple Squamous epithelial cells are found in the lung (alveoli), lining the lumen of blood vessels, and lymphatic vessels, and also in the kidneys.
Saquamous cells are flat cells. Single cell layer of these squamous cells is called saqumous cell epithelium. The stratified epithelium means formed of layers [strata] of cells which may or may not be squamous cells. The functions of these layers are different.