Here's why:
* Stratified epithelium is composed of multiple layers of cells.
* The cells in the basal (bottom) layer are actively dividing and have their nuclei located closer to the basement membrane.
* As cells mature and move towards the apical (top) surface, their nuclei may appear to be located at different levels within the cells due to the varying shapes and sizes of the cells in each layer.
Examples of stratified epithelium include:
* Stratified squamous epithelium: Found in the skin, mouth, esophagus, and vagina.
* Stratified cuboidal epithelium: Found in the ducts of glands like sweat glands and mammary glands.
* Stratified columnar epithelium: Found in the lining of the male urethra and some parts of the pharynx.
Important Note: While stratified epithelium is the main type with varying nuclear levels, it's important to understand that even within a single layer of cells, there can be slight variations in nuclear positions due to the natural arrangement and shape of cells. However, the consistent difference in nuclear levels is most prominent in stratified epithelial tissues.
