Epithelial cell

Epithelial cells make up the outer (i.e., skin) and inner (e.g., oral mucosa) linings of the body. They aggregate into layers of epithelium. Epithelial cells lining the skin, mouth, nose and anal canal derive from ectoderm. Those lining the respiratory system and the gastrointestinal tract derive from endoderm. Epithelial cells in the cardiovascular and lymphatic system derive from mesoderm.