Detailed Summary of Epithelial Tissue
Epithelial tissue serves as the protective covering for most organs and cavities in the animal body. This highly specialized tissue consists of closely packed cells arranged in continuous sheets with minimal intercellular spaces. Critical functions of epithelial tissues include protection, absorption, secretion, and sensation.
The classification of epithelial tissue can be based on cell shape and the number of cell layers. Main types include:
- Simple Squamous Epithelium: This consists of a single layer of flat cells and facilitates diffusion and filtration, commonly found in blood vessel linings and lung alveoli.
- Stratified Squamous Epithelium: Characterized by multiple cell layers that provide protection against abrasion, found in the skin and the lining of the mouth.
- Cuboidal Epithelium: Cube-shaped cells that line kidney tubules and glands, aiding in secretion and absorption.
- Columnar Epithelium: Tall, pillar-like cells found mainly in the intestinal lining; these can be ciliated, moving mucus in the respiratory tract.
- Glandular Epithelium: Specialized epithelial tissue that forms glands for secretion.
Each type of epithelium is connected to a basement membrane, which serves as a structural foundation and separates it from underlying tissues. The variety in epithelial cell shapes and arrangements reflects its diverse roles in maintaining the homeostasis and protecting the organism.
