Epithelial cells are the building blocks of epithelial tissue, which forms large sheets that cover the entire outer surface of the body and help form the skin. Squamous epithelial cells are thin and flat. These cells resemble fish scales. Simple squamous cells are arranged in one layer, while stratified squamous epithelial cells are arranged in two or more layers.
Simple or Stratified
Simple squamous epithelial cells arrange themselves in a single layer. Because the tissue they form is so thin, it is generally found in areas that need a thin membrane to allow the transport of nutrients or waste, diffusion or filtration. Stratified squamous epithelial tissue is formed when the cells arrange in two or more layers. These are the most common type of epithelium and are less likely to be damaged since they are thicker and stronger.
Simple squamous epithelial cells are found in the walls of the capillaries, in the air sacs, or alveoli, of the lungs, and in the kidneys. Stratified epithelial cells are located on the outer layer of the skin and they also all body openings.
Simple squamous epithelial cells perform a few vital functions for the human body. In the capillaries, they allow for the exchange of oxygen, nutrients and waste. The cells that are located in the lungs permit diffusion, or the transport, of oxygen and carbon dioxide. This is an essential part of circulation. The squamous cells found in the kidneys work to filter water and electrolytes.
The majority of cancers are cancer of the epithelial cells, also called carcinoma. Since squamous epithelial is found in most organs and across the skin, there is a potential for it to be affected in many areas. Squamous cell carcinoma is the second most common type of skin cancer and it is usually treatable.
Since squamous cell carcinoma is so common, it is important to know what can cause the disease. Sun exposure is a risk in all skin cancers. Radiation exposure, either environmental or therapeutic, is also a contributing factor to many cases of squamous cell carcinoma. An immune system that is not in top working order can also contribute to this disease. People with lighter skin are more prone to squamous cell carcinoma and all should limit their exposure to potential risks.
- The Human Body in Health and Illness; Barbara Herlihy, PhD, RN; 2003
- National Cancer Institute
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