Which type of epithelial cells are characterized as keratinized?

Keratinized epithelial cells are most commonly found in the stratified squamous epithelium. This type of epithelium consists of multiple layers of cells, with the outermost layer being made up of flattened cells that produce keratin, a protective protein. Keratin acts as a barrier to water loss and helps protect underlying tissues from environmental damage, such as mechanical abrasion and pathogens.

Stratified squamous epithelium is ideally suited for areas of the body that experience significant friction and wear, such as the skin. The keratinized layer provides an additional level of protection, making it resilient against damage from external factors. This structural characteristic is what distinguishes keratinized stratified squamous epithelium from other types of epithelial cells, which may not provide the same level of protection or possess this keratinized feature.

In contrast, other types of epithelial cells, like simple cuboidal, stratified columnar, and simple squamous, do not typically exhibit keratinization and serve different functions, such as secretion, absorption, or filtration, rather than providing protective barriers against external stressors.