Cuboidal epithelium is made of cube-like cells and is mainly involved in secretion and absorption.
Important points
- The cells of cuboidal epithelium resemble a cube.
- The length, breadth and height (thickness) of the cells are similar.
- Types:
- Simple cuboidal epithelium
- Stratified cuboidal epithelium
Simple cuboidal epithelium
- Made up of a single layer of cells.
- The cells are cube-like in shape.
- The nucleus is round.
- Examples:
- Germinal epithelium
- Follicular epithelium of the thyroid gland
- Lining of the distal convoluted tubule (DCT)
- Ascending limb of the loop of Henle
- Collecting tubule of the kidney
- Functions:
- Formation of gametes
- Helps in excretion
- Formation of the thyroxine hormone in the thyroid
NCERT’s examples of cuboidal epithelium are the ducts of glands and the tubular parts of nephrons, where it helps in secretion and absorption. In the proximal convoluted tubule (PCT), the cuboidal cells bear microvilli on their free surface, forming a brush border that increases the area for absorption.
Stratified cuboidal epithelium
- Made up of more than 6 layers of cells.
- Only the cells of the top layer are cube-like in shape.
- Examples:
- Ducts of mammary glands
- Ducts of sweat glands
- Functions:
- Helps in thermoregulation (sweat formation)
- Secretion of milk
Remember the shapes by their proportions: squamous cells are flat (wider than tall), cuboidal cells are as tall as they are wide, and columnar cells are taller than they are wide. Read more in Squamous Epithelium.