Simple Epithelial Tissue - Class 11 Biology Notes
Definition: Simple epithelial tissue is made of a single layer of cells. It forms the lining of
various internal and external surfaces and allows diffusion, absorption, filtration, and
secretion.
Characteristics:
• Single layer of cells.
• Cells rest on basement membrane.
• Thin and delicate for easy transport of materials.
• Little or no blood supply.
• Cells are tightly packed with little intercellular space.
Functions:
• Protection
• Absorption
• Secretion
• Filtration
• Diffusion
Types of Simple Epithelial Tissue:
1. Simple Squamous Epithelium
• Made of flat, thin cells like tiles.
• Allows diffusion and filtration.
Location: Alveoli of lungs, walls of capillaries, Bowman’s capsule of kidney.
2. Simple Cuboidal Epithelium
• Cube-shaped cells with central nucleus.
• Main function is secretion and absorption.
Location: Kidney tubules, salivary glands, thyroid gland.
3. Simple Columnar Epithelium
• Tall, pillar-like cells.
• Helps in absorption and secretion.
Location: Lining of stomach and intestine.
4. Ciliated Epithelium
• Columnar or cuboidal cells with hair-like cilia on free surface.
• Cilia move substances like mucus or ova in one direction.
Location: Respiratory tract, fallopian tubes.
5. Glandular Epithelium
• Modified columnar epithelium specialized in secretion.
• Forms glands like sweat glands and salivary glands.
Definition: Simple epithelial tissue is made of a single layer of cells. It forms the lining of
various internal and external surfaces and allows diffusion, absorption, filtration, and
secretion.
Characteristics:
• Single layer of cells.
• Cells rest on basement membrane.
• Thin and delicate for easy transport of materials.
• Little or no blood supply.
• Cells are tightly packed with little intercellular space.
Functions:
• Protection
• Absorption
• Secretion
• Filtration
• Diffusion
Types of Simple Epithelial Tissue:
1. Simple Squamous Epithelium
• Made of flat, thin cells like tiles.
• Allows diffusion and filtration.
Location: Alveoli of lungs, walls of capillaries, Bowman’s capsule of kidney.
2. Simple Cuboidal Epithelium
• Cube-shaped cells with central nucleus.
• Main function is secretion and absorption.
Location: Kidney tubules, salivary glands, thyroid gland.
3. Simple Columnar Epithelium
• Tall, pillar-like cells.
• Helps in absorption and secretion.
Location: Lining of stomach and intestine.
4. Ciliated Epithelium
• Columnar or cuboidal cells with hair-like cilia on free surface.
• Cilia move substances like mucus or ova in one direction.
Location: Respiratory tract, fallopian tubes.
5. Glandular Epithelium
• Modified columnar epithelium specialized in secretion.
• Forms glands like sweat glands and salivary glands.
