Epithelial cells are specialized according to the function and location of the organ:
Simple Squamous Epithelium: Found in areas where rapid diffusion or filtration is needed, such as blood vessels and alveoli of the lungs. Simple Cuboidal Epithelium: Lines ducts and tubules, including kidney tubules and glandular ducts, for secretion and absorption. Simple Columnar Epithelium: Lines the gastrointestinal tract and is involved in absorption and secretion. Stratified Squamous Epithelium: Protects against abrasion and is found in the skin, mouth, and esophagus. Pseudostratified Columnar Epithelium: Lines the respiratory tract and has cilia to move mucus and trapped particles. Transitional Epithelium: Lines the urinary bladder and can stretch to accommodate urine volume.
