Epithelial Tissue: Classification (location and function) ch.4

How to classify Epithelia:

1. Number of Cell Layers

• Simple → found in protected (internal) areas

• Stratified → found in areas of mechanical/chemical stress

2. Shape of cell (at apical (free) surface)

• Squamous

• Cuboidal

• Columnar

How many layers are in simple and stratified cells?

Simple = 1

Stratified = 2+

Classify the following cells based on shape:

*Note how the nuclei of the cells take on the same shape as the cells

What are the types of simple epithelium?

Simple epithelium: One cell layer thick, all cells are tightly bound together and attached directly to the basement membrane

Types:

• Simple squamous

• Simple cuboidal

• Simple columnar

• Pseudo-stratified columnar

What are the types of stratified epithelium?

Stratified epithelium: Two or more layers thick, only the deepest layer directly attaches to the basement membrane

Types:

• Stratified squamous keratinized

• Stratified squamous nonkeratinized

• Stratified cuboidal

• Stratified columnar

• Transitional