Squamous epithelial cells are found in the inner lining of
- (a)Oesophagus.
- (b)Small intestine.
- (c)Ducts of salivary gland.
- (d)Kidney.
Correct — A, Oesophagus. Squamous epithelium is made of flat, thin, tile-like cells that suit surfaces needing a smooth, protective lining or easy diffusion. The oesophagus is lined by stratified squamous epithelium, which protects against abrasion from swallowed food. The other listed sites are lined by different epithelial types.
- (b)Small intestine. — The small intestine is lined by columnar epithelium with microvilli, shaped for absorption of digested food — not squamous cells.
- (c)Ducts of salivary gland. — The ducts of glands such as salivary glands are lined by cuboidal epithelium, not flat squamous cells.
- (d)Kidney. — Kidney tubules are lined mainly by cuboidal epithelium suited to secretion and absorption; the tissue is not squamous.
Epithelial tissue covers body surfaces and lines cavities, and its cell shape matches its job. Squamous (flat, scale-like) cells form smooth linings and thin diffusion barriers; cuboidal cells line ducts and tubules for secretion/absorption; columnar cells line the gut for absorption and secretion. The oesophagus needs a tough, protective lining, so it has stratified squamous epithelium.
This is a shape-to-site matching question. Recall the pattern: squamous for protective/diffusion surfaces (oesophagus, mouth lining, alveoli, blood-vessel lining); cuboidal for ducts and kidney tubules; columnar for the intestine. Matching each option to its typical epithelium isolates the oesophagus as the squamous-lined organ.
- Squamous epithelium = flat, thin cells forming smooth protective linings or diffusion surfaces.
- The oesophagus is lined by stratified squamous epithelium that resists abrasion.
- Cuboidal epithelium lines gland ducts and kidney tubules; columnar epithelium lines the small intestine.
- Simple squamous epithelium also lines the alveoli of the lungs and the inner walls of blood vessels.
- Assuming all gut and gland linings are the same — the oesophagus is squamous but the intestine is columnar.
- Forgetting that kidney tubules and gland ducts are cuboidal, not squamous.
Asked by matching an epithelial type to the organ it lines, or by identifying the epithelium of a given site (oesophagus, intestine, kidney, alveoli).
No directly related past PYQ was found.
- practice — not a real PYQ
The inner lining of the small intestine is made of
- (a)squamous epithelium
- (b)columnar epithelium
- (c)cuboidal epithelium
- (d)nervous tissue
Answer(b) columnar epithelium — with microvilli that increase the surface for absorption.
- practice — not a real PYQ
Simple squamous epithelium is best suited for
- (a)secretion in glands
- (b)rapid diffusion across a thin surface
- (c)conducting impulses
- (d)contraction
Answer(b) rapid diffusion across a thin surface — as in the alveoli and blood-vessel walls.