L2.4: Simple Epithelia

• Simple Epithelia

  • Simple Squamous Epithelium
  • Simple Cuboidal Epithelium
  • Simple Columnar Epithelium
  • Pseudostratified Columnar Epithelium
• Definition

  • Single layer of thin squamous cells (flat cells).
  • Usually forms membranes for filtration, exchange of substances (diffusion), or secretion.
  • Cells fit closely together


  Simple Squamous Epithelium
• Location

  • Air sacs or the alveoli
  • Walls of capillaries
  • Serous membranes that line and cover the ventral body cavity organs.


  simple squamous epithelium
• Functions

  • absorption
  • secretion
  • filtration



  simple squamous epithelium
• Definition

  • Single layer of cube-like cells.
  • Resting on a basement membrane.
  • Forms walls of the kidney tubules and covers the surface of the ovaries.
  • One layer of cuboidal cells mainly for filtration.


  simple cuboidal epithelium
• Location

  • Glands and their ducts (salivary/pancreas).
  • Wall of the kidney tubules.
  • Surface of the ovaries.


  simple cuboidal epithelium
• Function

  • secretion
  • absorption (Ciliated types propel mucus or reproductive cells)



  simple cuboidal epithelium
• Definition

  • Single layer of tall cells.
  • Goblet Cells: glands that produce lubricating mucus.: “Why we have slimy internal organs.”
  • Functions in secretion and absorption, and propels mucus or reproductive cells.
  • Nuclei appear in a straight line
  • Microvilli – Microscopic Hair-like structure
  • Microvilli has an absorptive ability that increases the surface area of the epithelium.


  simple columnar epithelium
• Location

  • Entire length of the digestive tract (from stomach to anus).
  • Mucous membranes that line body cavities open to the body exterior.


  simple columnar epithelium
• Function

  • secretion
  • absorption



  simple columnar epithelium