Epithelial tissue is one of the four primary types of tissue in the human body. It covers the body's surface, lines internal organs, and forms glands. This tissue is composed of tightly packed cells arranged in continuous sheets.
Types of Epithelial Tissue
There are several types of epithelial tissue, including:
Squamous epithelium: These cells are flat and thin, forming the lining of the blood vessels, alveoli of the lungs, and parts of the kidney.
Cuboidal epithelium: These cells are cube-shaped and are found in the kidney tubules and various glands.
Columnar epithelium: These cells are tall and rectangular, lining the digestive tract and parts of the respiratory system.
Transitional epithelium: These cells can change shape, found in the urinary bladder.
Functions of Epithelial Tissue
Epithelial tissue serves several important functions, including:
Protection: It acts as a barrier to protect underlying tissues from physical and chemical injury.