What is Stratified Squamous Epithelium?
Stratified squamous epithelium is a type of
epithelial tissue composed of multiple layers of cells. The cells in the basal layer are typically cuboidal or columnar, while the cells in the superficial layers are flattened and squamous. This tissue type serves as a protective barrier against mechanical stress, pathogens, and water loss.
Keratinized: Found in areas exposed to the external environment, such as the skin's epidermis. The cells in the outermost layer are dead and filled with keratin, a tough, protective protein.
Non-Keratinized: Found in moist, internal surfaces such as the oral cavity, esophagus, vagina, and anus. These cells remain alive and do not have keratin.
What is the Function of Stratified Squamous Epithelium?
The primary function of stratified squamous epithelium is to provide protection. The multiple cell layers make it well-suited to withstand abrasion and friction. The keratinized variety offers additional protection against
dehydration and infection by forming a tough, impermeable barrier.
Basal Layer: The deepest layer, consisting of
cuboidal or columnar cells. Cells in this layer are actively dividing.
Intermediate Layers: Above the basal layer, these cells start to flatten as they move towards the surface.
Superficial Layer: The outermost layer, where cells are flattened and squamous. In keratinized epithelium, these cells are dead and filled with keratin.
How is Stratified Squamous Epithelium Identified Histologically?
Under a microscope, stratified squamous epithelium can be identified by its multiple layers and the progressive flattening of cells from the basal to the superficial layers. In keratinized epithelium, the presence of a thick, eosinophilic keratin layer is a distinguishing feature.
Histological staining techniques, such as Hematoxylin and Eosin (H&E), are often used to visualize these structures.
Conclusion
Stratified squamous epithelium plays a vital role in protecting the body from mechanical damage, pathogens, and dehydration. Its unique structure and ability to renew itself make it an essential component of various tissues and organs. Understanding its histological characteristics and clinical significance is crucial for diagnosing and treating related conditions.