Figure 2-1. Epithelial cells.
2-6. TYPES OF EPITHELIAL TISSUES
a. Layers. In epithelial tissues, the cells are in single or multiple layers. If there
is only one layer, the tissue is called a simple epithelium. If there is more than one
layer, the tissue is called a stratified epithelium. See figure 2-2.
Figure 2-2. Types of epithelial tissues.
b. Naming. Epithelial tissues are named by the number of layers and the type
of cell in its outermost layer. For example, if there are several layers and if the
outermost layer consists of squamous (flat) cells, then the tissue is called a stratified
c. Examples of Epithelial Tissues.
(1) A simple squamous epithelium called endothelium lines the heart and
(2) As serous membranes, simple squamous epithelial tissue lines the
cavities of the abdomen (peritoneal lining) and the chest (pleural lining). Serous
membranes are membranes which secrete a lubricating fluid.
(3) Epithelial tissue forms the secretory part of glands and also parts of the
various sense organs.