Final answer:
Epithelial tissues have several special characteristics that distinguish them from other tissue types. These include being highly cellular, having cell junctions, exhibiting polarity, being attached to a basal lamina and basement membrane, and having specific functions depending on their location.
Step-by-step explanation:
Epithelial tissues have several special characteristics that distinguish them from other tissue types:
- Highly cellular: Epithelial tissues are made up of closely packed cells with little or no extracellular material between them.
- Cell junctions: Adjoining cells in epithelial tissues form specialized intercellular connections called cell junctions, which help maintain tissue integrity.
- Polarity: Epithelial cells exhibit polarity, with differences in structure and function between their apical facing surface (exposed to the external environment) and basal surface (close to underlying body structures).
- Basal lamina: Epithelial tissues are attached to a basal lamina, which is a mixture of glycoproteins and collagen. It separates the epithelium from underlying connective tissue.
- Basement membrane: The basal lamina attaches to a reticular lamina secreted by underlying connective tissue, forming a basement membrane that helps hold the epithelium together.
- Specific functions: Epithelial tissues have specific functions depending on their location, such as protection, absorption, secretion, and filtration.