L2.3: Classification of Epithelia

• Classification of Epithelia

  • According to number of layers
  • simple epithelium
  • stratified epithelium
  • According to shape
  • squamous cells
  • cuboidal cells
  • columnar cells
• one layer of cells

  simple epithelium
• • More than one cell layer.
  • Stratified epithelia are named for the cells at the free surface of the epithelial membrane.
  • [1] stratified squamous epithelium
  • [2] simple squamous epithelium


  stratified epithelium

  A) 1

  B) 2

  
• Flattened like fish scales (squam = scale).


  squamous cells
• Cube-shaped like dice.

  cuboidal cells
• shaped like a column

  columnar cells
• cell shape - simple - stratified

  • squamous - Diffusion and filtration secretion in serous membranes. - protection
  • cuboidal and columnar - Secretion and absorption; ciliated types propel mucus or reproductive cells. - Protection; these tissue types are rare in humans.
  • transitional - ... - Protection; stretching to accommodate distension of urinary structures.
• Stratified Epithelia

  • Stratified Squamous Epithelium
  • Stratified Cuboidal Epithelium
  • Stratified Columnar Epithelium