Question

Where does squamous epithelium form a selectively permeable surface?

Answer 1

Epithelium is a tissue layer which lines the inner surface of all blood arteries (endothelium), the alveolar sacs in the lung, and the body cavities (mesothelium). The basic function of simple squamous epithelia is to let gases and tiny molecules to diffuse more easily.

Complete answer:
At the lining of blood vessels, squamous epithelium produces a selectively permeable surface.
There are 3 different types of epithelial tissue: squamous, cuboidal, and columnar.
Squamous epithelium : The number of cell layers and the structure of the cells are used to classify epithelial tissue. Squamous, cuboidal, and columnar cells. Simple (one layer) and stratified cell layers (multiple layers).
Stratified cuboidal epithelium: Found in Sweat glands.
Simple cuboidal epithelium: found In ducts.
Stratified columnar epithelium: Found in Male urethra, etc.
Endothelium lines the inner surface of all blood arteries, forms the wall of alveolar sacs in the lung, and lines the body cavities (mesothelium). The basic function of simple squamous epithelia is to let gases and tiny molecules to diffuse more easily. Like flakes or fish scales, squamous epithelial cells appear crushed or flattened. The cells are wider than they are tall, with an oval-shaped nucleus.
A single layer of flat cells in contact with the epithelium's basal lamina (one of the two layers of the basement membrane) makes up a simple squamous epithelium. Small molecules must flow swiftly through membranes via filtration or diffusion, and this type of epithelium is often permeable.
The intestine is the place where absorption of nutrients takes place. For this function, tall columnar cellular lining is utilized.
Oviduct carries out the function of pushing the fertilized ovum or zygote towards the uterus. For this purpose, the inner surface of the oviduct is lined by ciliated epithelium.

Note:-
The mesothelium is a basic squamous epithelium that borders bodily cavities and internal organs and forms the surface layer of the serous membrane. Its main purpose is to provide a smooth, protected surface. Squamous epithelial cells that release a fluid that lubricates the mesothelium are known as mesothelial cells.