Suppose, due to an accident, the delicate lining of the mouth and the oesophagus of a person is injured. In this case, which one of the following tissues will be affected?
- A.Smooth muscle
- B.Cuboidal epithelium
- C.Squamous epithelium
- D.Striated muscle
Correct answer
Explanation
The correct answer is C, Squamous epithelium. The inner lining of the mouth and the oesophagus is made of squamous epithelium, so an injury to that lining damages this tissue.
Squamous epithelium is made of thin, flat cells fitted together like tiles. It forms a smooth protective covering. A single layer lines blood vessels and the air sacs of the lungs, where substances must pass through easily. In the mouth and oesophagus, which face rubbing from food, the cells are arranged in many layers, called stratified squamous epithelium, and the outer layer of the skin is of the same type.
A is wrong: smooth muscle lies in the deeper walls of the oesophagus and moves food by peristalsis; it is not the lining.
B is wrong: cuboidal epithelium, with cube-shaped cells, lines kidney tubules and the ducts of salivary glands.
D is wrong: striated muscle is the voluntary muscle attached to bones, not the lining of the mouth.
Exam tip: squamous – mouth, oesophagus, skin, blood vessels; cuboidal – kidney tubules, gland ducts; columnar – inner lining of the intestine; ciliated – windpipe.
Practice Questions
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- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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