Study Set Content:
- forms a thick epithelium because it consists of several layers of cells.
Stratified squamous epithelium
There are two types of stratified squamous epithelia:
keratinized stratified squamous and nonkeratinized stratified squamous epithelia.
The outer layer of the skin is comprised of a
keratinized squamous epithelium.
- reduces the loss of water from the body.
keratin
Stratified squamous epithelium of the mouth is a
moist nonkeratinized stratified squamous epithelium.
This nonkeratinized stratified squamous epithelium provides protection
- against abrasion and acts as a mechanical barrier.
Several layers of cells that are cuboidal in the basal layer and progressively flattened toward the surfaces; the epithelium can be nonkeratinized (moist) or keratinized; in nonkeratinized stratified squamous epithelium, the surface cells retain a nucleus and cytoplasm; in keratinized stratified epithelium, the cytoplasm of cells at the surface is replaced by a protein called keratin, and the cells are dead
Stratified Squamous epithelium
Function Stratified Squamous epithelium
protects against abrasion, forms a barrier against infection, and reduces loss of water from the body
Location: Stratified Squamous epithelium
Keratinized – outer layer of the skin; Nonkeratinized – mouth, throat, larynx, esophagus, anus, vagina, inferior urethra, and corneas
- is a special type of stratified epithelium that can be greatly stretched.
Transitional epithelium
The shape of the cells change as the epithelium is
stretched
- ines cavities that can expand greatly, such as the urinary bladder.
- It also protects underlying structures, like the urinary bladder, from the caustic effects of urine.
Transitional Epithelium
Stratified cells that appear cuboidal when the organ or tube is not stretched and squamous when the organ or tube is stretched by fluid
Transitional Epithelium
Transitional epithelium function
Accommodates fluctuations in the volume of fluid in an organ or a tube; protects against the caustic effects of urine
Location of transitional epithelium
Lining of urinary bladder, ureters, and superior urethra
The free surface can be smooth or lined with
microvili or cilia
- move materials over the top of the cell.
Cilia
- increase surface area.
Microvili
- Cells have several structures that hold one cell to one another or to the basement membrane.
These structures do three things;
- mechanically bind the cells together, help form a permeability barrier, and provide a mechanism for intercellular communication.
- are mechanical links that bind cells together.
Desmosomes
