Which tissue forms the covering of all body surfaces, lines body cavities and hollow organs, and is the major tissue in glands?

• A. Connective Tissue
• B. Epithelial Tissue
• C. Muscle Tissue
• D. Nervous Tissue

Answer: (B)

The main idea is that tissues have specialized roles, and one type is specialized for covering and lining structures. Epithelial tissue forms the covering of all body surfaces, lines body cavities and hollow organs, and is the major tissue in glands. Its cells are packed tightly into continuous sheets, creating a protective barrier that also participates in absorption, secretion, and filtration. This tissue lines the skin and mucous membranes, the lining of the digestive and respiratory tracts, and the ducts and secretory parts of glands. Glands themselves arise from this tissue, with endocrine glands releasing hormones into the bloodstream and exocrine glands releasing substances into ducts or surfaces.

Epithelial tissue is typically avascular, so it relies on the underlying tissues for nutrients, and it regenerates rapidly after injury, which helps keep surfaces protected and functional. In contrast, connective tissue mainly provides support and binding, muscle tissue causes movement through contraction, and nervous tissue transmits electrical signals.