EasyBiologyHigh School (11–12)Tissues and Organs › Structural Organisation in AnimalsConceptualA-LevelIB
Each clue below describes one epithelium…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Each clue below describes one epithelium. Name it in full, with the number of layers and the shape of the cells.
- A single thin layer of flat cells in the wall of an air sac of the lung.
- Cells with beating hairs on the free surface, lining the fallopian tube.
- Many layers of cells that cover the skin and protect it.
- A single layer of tall cells with microvilli, lining the small intestine.
- A single layer of cube shaped cells, lining a tubule of the kidney.
Need a reminder? The key ideaShow
Epithelial tissue forms sheets that cover the body and line its cavities and tubes. It has little matrix and no blood vessels, and it rests on a basement membrane. Simple epithelium has one layer, and compound epithelium has more. The cells are squamous (flat), cuboidal (cube shaped) or columnar (tall). Simple squamous epithelium lines blood vessels and air sacs and forms a thin boundary for diffusion. Cuboidal epithelium lines gland ducts and kidney tubules and helps in secretion and absorption. Columnar epithelium lines the stomach and intestine. Ciliated epithelium moves mucus or particles. Compound epithelium protects, as in the skin. The rate of diffusion across a layer is inversely proportional to its thickness.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) One layer of flat cells: simple squamous epithelium. It forms a thin boundary for diffusion.
Step 2. (b) Cells with cilia: ciliated epithelium. It moves particles or mucus in one direction.
Step 3. (c) Many layers: compound (stratified) epithelium. It protects.
Step 4. (d) One layer of tall cells: simple columnar epithelium. The microvilli increase the area for absorption.
Step 5. (e) One layer of cubes: simple cuboidal epithelium.
Answer: (a) simple squamous; (b) ciliated; (c) compound; (d) simple columnar; (e) simple cuboidal.
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