This website was developed by undergraduate biology researchers working with Dr. Karen Bernd at Davidson College.

Stratified Epithelium


What is It?

  • not simple - cells do not make up a single layer
  • cells compose multiple layers
  • specialized depending on the location and function of epithelial cells


Classifications

 

Stratified Squamous Epithelia

Image from: http://www.pathguy.com/histo/090.jpg.Permission pending.

  • flat, scale-like
  • can be multi-layered
  • basal layer is in contact with basal lamina (the collagen membrane between the epithelia and capillaries)
  • selectively permeable - filtration/diffusion
  • provide protection against:
    • mechanical friction - rubbing and physical trauma from external sources
    • chemical damage - environmental and internal chemicals/compounds degrading epithelial lining
  • alveoli - cell layer essential for gas exchange, also a protective layer against air-born pathogens/toxic gases
  • lining of the esophagus - protection of the esophagus from stomach acid, non-keratinized, mucousal cell layer

 

Stratified Columnar Epithelia

Image from: http://www.cytochemistry.net/microanatomy/epithelia/salivary8.jpg.Permission pending.

  • rare
  • column-shaped
  • secretion and protection
  • often found between simple columnar epithelia and stratified squamous epithelia
  • found near salivary glands - cell lining protects the salivary duct, goblet cells found between the cells
  • found in vas deferens where it protects and aids in secretion of glands
  • intestinal lining - ciliated to help move nutrients and increase absorption, also protects against pathogens/bacteria
  • also form layers in ocular conjunctiva and the linings of the pharynx, anus, uterus, urethra


Stratified Cuboidal Epithelia

Image from: http://www.kumc.edu/instruction/medicine/anatomy/histoweb/epithel/small/Epth017s.JPG.Permission pending.

  • rare
  • cube-shaped
  • commonly cells make up two layers
  • protection of larger ducts -cell layers surround/protect gland ducts
  • sweat glands in the skin
  • mammary gland in the breast
  • salivary glands in the mouth
  • may be active (pump material in/out of lumen)

 

Specializations
Resources

http://ect.downstate.edu/courseware/histomanual/epithelia.html

http://www.cytochemistry.net/microanatomy/epithelia/stratified_squamous.htm

http://www.cytochemistry.net/microanatomy/epithelia/stratified_columnar.htm

http://www.courseweb.uottawa.ca/medicine-histology/english/ss_basictissues/epithelia.htm

Send comments, concerns or questions to Dr. Karen Bernd