What are the common layers found in epithelial tissues?
In epithelial tissues, layers are classified based on the number of cell layers and the shape of the cells. The common layers are:
1. Simple Epithelium: A single layer of cells that is involved in absorption, secretion, and filtration. Examples include the lining of the alveoli in the lungs and the endothelium lining blood vessels. 2. Stratified Epithelium: Multiple layers of cells which provide protection against abrasion. Examples include the skin's epidermis and the lining of the esophagus. 3. Pseudostratified Epithelium: Appears to have multiple layers due to the varying positions of nuclei within the cells, but each cell touches the basement membrane. Found in the respiratory tract.
