Stratified epithelium is a type of tissue found in the human body. It consists of multiple layers of cells that provide protection against mechanical and chemical damage. The phonetic transcription of this word in IPA symbols is /ˈstrætɪfaɪd ɛpɪˈθiːliəm/. The first syllable is pronounced as "strat" with a short "a" sound, followed by "i" and "f" sounds. The second syllable is pronounced with a long "i" and "ɛ" sounds. The final syllable is pronounced as "lium" with an "ɪ" and "ʌ" sound.
Stratified epithelium refers to a type of tissue found in the human body, specifically within the epithelial layer of various organs and structures. Epithelial tissues function as protective barriers and are found covering and lining different surfaces of the body such as the skin, respiratory tract, gastrointestinal tract, and reproductive organs.
The term "stratified" refers to the multiple layers that make up this type of epithelium. In stratified epithelium, several layers of cells are stacked on top of each other. The basal layer, also known as the basal membrane, is at the bottom and is in direct contact with the underlying connective tissue. The cells in this layer are typically cuboidal or columnar in shape.
As the layers progress towards the surface, the cells gradually change shape. The middle layer consists of irregularly-shaped cells, while the outermost layer consists of flat and squamous-like cells. This arrangement allows for increased protection and durability compared to simpler types of epithelia.
The presence of multiple layers in stratified epithelium provides strength, resilience, and protection against mechanical stress, friction, and potential damage from external factors. Its location within organs and structures that undergo constant wear and tear, such as the skin and lining of the respiratory tract, highlights its critical role in maintaining tissue integrity.
Stratified epithelium can be further classified into different subtypes based on the shape of the outermost layer of cells. Examples include stratified squamous epithelium, stratified columnar epithelium, and transitional epithelium. The specific subtype present in different body locations reflects the functional requirements and environmental conditions of those regions.
E. Occurring in the form of several superposed layers, the cells differing in shape in the different layers.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "stratified" in stratified epithelium originated from the Latin word "stratum", which means "a layer". This refers to the layered arrangement of cells in this type of epithelium. The term "epithelium" comes from the Greek word "epithelioma", which means "a layer upon a base". It is a combination of "epi", meaning "upon", and "thelium", meaning "a layer" or "covering". Thus, the word "stratified epithelium" describes a type of tissue that consists of multiple layers of cells forming a protective covering.