A group of cells with similar structure and function, as well as similar extracellular substances located between cells.
Tissues
study of tissues
histology
4 types of tissues
Found throughout the body where it covers internal and external surfaces. It also forms most of the glands.
epithelial tissue
epithelial tissue is composed of layer of epithelial cells with one surface which is not in contact with other cells.
free surface or apical surface
attaches the epithelial cells (basal surface) to
underlying tissues.
basement membrane
Functions of epithelial tissue
epithelial tissue can be classified according to
simple epithelium
more than one layer of cells
stratified epithelium
pseudostratified columnar epithelium
simple squamous
simple cuboidal epithelium
simple columnar epithelium
forms a thick epithelium because it consists of many layers of cells.
stratified squamous epithelium
2 classifications of stratified squamous
forms outer layer of skin and provides protection against abrasion
keratinized
the moist part of the epithelium and prevents surfaces from drying out
non-keratinized
transitional epithelium
2 classifications of transitional epithelium
function of epithelium in terms of number of cell layers
movement of materials (diffusion, filtration, secretion and absorption)
simple
function of epithelium in terms of number of cell layers
protection
Stratified
function of epithelium in terms of number of cell layers
cleaning
pseudostratified
function of epithelial tissue In terms of cell shape
diffusion and filtration
squamous