NEET PG DENTAL EXAM

Detailed explanation-1: -The apical surface of epithelial cells, which lines the lumen of sac-and tube-shaped organs and the inner surfaces of the body cavities, forms the interface between the extracellular milieu and underlying tissues.

Detailed explanation-2: -The upper surface of epithelium is free, or exposed to the outside of the body or to an internal body cavity. The basal surface rests on connective tissue. A thin, extracellular layer called the basement membrane forms between the epithelial and connective tissue.

Detailed explanation-3: -Although large exocrine glands like the liver and pancreas may appear solid, each secretory cell has an apical surface exposed to a lumen. This lumenal space, in turn, leads through ducts to the outside of the body.