Where is epithelial tissue found?

Epithelial tissue is found throughout the body, and is responsible for lining body cavities, and forming the covering of hollow organs and body tissues. In the skin, it consists of keratinized stratified epithelium, which is rigid, highly impermeable, and self-renewing in structure and function. Epithelial tissue is also found in the lining of intestines, simple columnar epithelial cells typically line the stomach and intestines, and assist in absorption and secretion. These cells are assembled in a row with nuclei present at the same level in the tissue. Pseudostratfied columnar epithelial cells line the upper respiratory tract and typically consist of many cilia. The ciliated cells are found across the apical surface and regulate the movement of mucus across the respiratory tract. In the urinary system, the transitional epithelial tissue allows for the bladder to stretch, and allow it to hold more urine.