Epithelial tissue layers

Epithelial tissue notes

Epithelial cells derive from all three major embryonic layers. Epithelial tissue also has a sensory function as it contains sensory nerves in areas such as the skin, tongue, nose, and ears. Figure 1. The basal lamina attaches to a reticular lamina, which is secreted by the underlying connective tissue, forming a basement membrane that helps hold it all together. Squamous cell nuclei tend to be flat, horizontal, and elliptical, mirroring the form of the cell. Other functions of endothelial cells include: Macromolecule Transport Regulation Endothelium regulates the movement of macromolecules, gases, and fluid between the blood and surrounding tissues. It protects the internal structures of the body from damage and dehydration. In the intestines, this tissue absorbs nutrients during digestion. The cells here may possess microvilli for maximising the surface area for absorption and these microvilli may form a brush border. New York: Garland Science;

The endothelial cells in the brain that form the blood-brain barrier, for instance, are highly selective and allow only certain substances to move across the endothelium.

For example, simple squamous epithelial tissue describes a single layer of cells that are flat and scale-like in shape. An example of this is found in mammalian skin that makes the epithelium waterproof. In general, it is found where absorption and filtration occur.

National Cancer Institute. Some epithelia often include structural features that allow the selective transport of molecules and ions across their cell membranes. The alveoli of lungs where gases diffuse, segments of kidney tubules, and the lining of capillaries are also made of simple squamous epithelial tissue.

epithelial tissue characteristics

Figure 1.

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The Function and Cell Types of Epithelial Tissue