Squamous epithelial cells

Squamous epithelial cells are a type of epithelial cell that are flat and scale-like in appearance. They are one of the three main types of epithelial tissue, along with cuboidal epithelial cells and columnar epithelial cells. Squamous epithelial cells are found in many parts of the body, including the skin, the mouth, the esophagus, and the lungs.

Structure

Squamous epithelial cells are thin and flat, with a shape that is similar to a fried egg. The nucleus is usually located in the center of the cell. These cells are arranged in a single layer (simple squamous epithelium) or multiple layers (stratified squamous epithelium). In the stratified squamous epithelium, the cells at the surface are flat, while those at the base are more cuboidal in shape.

Function

The primary function of squamous epithelial cells is to provide a barrier that prevents the entry of foreign substances and pathogens into the body. They also play a role in the diffusion of substances in and out of the bloodstream. In the lungs, for example, squamous epithelial cells facilitate the exchange of oxygen and carbon dioxide between the air and the blood.

Clinical significance

Abnormalities in squamous epithelial cells can lead to various medical conditions. For instance, squamous cell carcinoma is a type of cancer that originates from these cells. It is the second most common type of skin cancer and can also occur in other parts of the body, such as the mouth, esophagus, and lungs.

Pap smear is a common medical test that involves the examination of squamous epithelial cells from the cervix to detect cervical cancer and its precursors. Changes in the shape, size, or number of these cells can indicate the presence of the disease.

See also

• Epithelium
• Cuboidal epithelial cell
• Columnar epithelial cell
• Squamous cell carcinoma
• Pap smear