part of part of has characteristic squamous epithelial cell stratified epithelial cell stratified squamous epithelial cell Stratified squamous epithelial cells are a specific type of epithelial cell that form layers and have a flat shape. These cells are part of the outermost layer of the skin, called the epidermis, and are also found lining surfaces of the body that are subjected to physical or chemical wear and tear, such as the mouth, esophagus, and vagina. The primary role of these cells is to create a barrier that protects underlying tissues from dehydration, abrasion, and infection. The stratified squamous epithelium is able to provide a strong, force-resistant barrier due to the stratified arrangement of the cells; it consists primarily of keratinocytes in various stages of differentiation: The basal layer contains cells that continuously divide and push older cells towards the surface. As the cells move up through the layers, they gradually flatten and become filled with a protein called keratin. In high-abrasion areas like the skin, the outer layers of these cells can become so filled with keratin that they die (they become 'keratinized'), providing an even more robust barrier; eventually, they are shed off in a process known as desquamation. In addition to forming a protective barrier, stratified squamous epithelial cells also play a part in the immune response. They can recognize pathogens, and in response, release chemical signals that attract immune cells to the site of potential infection. Moreover, they also carry out a variety of interactions with the immune system to ensure that invading pathogens cannot penetrate into deeper layers of the body. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) A stratified epithelial cell that is part of squamous epithelium, characterized by multiple layers of cells. The basal layer is directly attached to the basement membrane and the apical layer consists of flattened squamous cells. This provides a protective barrier, commonly found in areas subject to abrasion, such as the skin, oral cavity, and esophagus. ZFA:0009144 https://cellxgene.cziscience.com/cellguide/CL_0000240 flattened multilaminar epithelium