Simple Epithelial Tissue

Study Notes

Simple epithelial tissues are one cell layer thick on a basement membrane.
There are three main types: simple squamous, cuboidal, and columnar.
Simple squamous epithelial tissue is the thinnest lining and is found in areas where there is no friction and substances need to pass through the tissue wall.
Examples of where simple squamous epithelial tissue is found include blood vessel walls and ureters.
Cuboidal epithelial tissue is found in kidney tubules and oviduct.
Columnar epithelial tissue often has cilia lining its free surface and is called ciliated columnar epithelial tissue.
Single-celled glands, called goblet cells, produce mucus, which is moved along by the cilia in columnar epithelial tissue.
This 'conveyor belt' system is useful in places such as the nasal cavity, liver, and digestive tract.

Compound epithelial tissues are more than one-cell-layer thick on a basement membrane.
There are two main types: stratified squamous and transitional.
Stratified squamous epithelial tissue is found in areas subject to trauma, such as the oral cavity, esophagus, and skin.
The skin has been infiltrated by keratin, which makes it appear different.
Different areas of the skin are more keratinized than others, such as foot pads.
Transitional epithelial tissue is found in the bladder and urethra.
Transitional epithelial tissue has the ability to expand greatly, which is useful as the bladder fills with urine.
When the bladder fills, the number of cell layers is greatly reduced.