EPITHELIAL TISSUES

Squamous Epithelium
Squamous epithelium, a single-layered tissue with flat, thin cells, plays several key roles in the body. Due to its thinness, it excels at facilitating the passive diffusion of gases, such as oxygen and carbon dioxide, across itself. This makes it ideal for lining the air sacs in the lungs (alveoli) and blood vessels. In other locations, like the lining of body cavities, it functions as a selective barrier, allowing some substances to pass through while restricting others. Squamous epithelium can also secrete lubricating fluids to reduce friction in certain areas. Overall, this versatile tissue is essential for gas exchange, filtration, and protection in various bodily systems.

Cuboidal Epithelium
Cuboidal epithelium, a type of epithelial tissue, consists of cube-shaped cells arranged in a single layer. These cells are powerhouses for functions like secretion, absorption, and protection. Due to their rich cytoplasm, they can carry out these processes efficiently. Cuboidal epithelium lines various organs throughout the body, including glands, kidneys, and ovaries. The specific function of this epithelium depends on its location within the body.

Columnar Epithelium
Columnar epithelium is a type of tissue that lines various organs in your body. It consists of tall, column-shaped cells packed tightly together in a single layer. These cells play a major role in absorption, secretion, and protection. Some examples of organs lined with columnar epithelium include the intestines, stomach, and respiratory tract.

Sources:
Cleveland Clinic, Epithelium: What It Is, Function & Types.
National Cancer Institute