Simple Squamous Epithelium

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Simple Squamous Epithelium

• Single layer of flat cells
• lines blood vessels (endothelium), closed body
  cavities (mesothelium)
• very thin --- controls diffusion, osmosis and
  filtration
• What is the primary function of this tissue
  (protection or transport)? (Hint What is its
  function as an endothelium,as mesothelium?)

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Examples of Simple Squamous Epithelium

• Section of intestine showing serosa

• Surface view of lining of peritoneal cavity

Is this endothelium, mesothelium, or neither?
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Simple Cuboidal Epithelium

• Single layer of cube-shaped cells viewed from the
  side
• Where would you find simple cuboidal epithelium
  in the body? Does it typically function in
  protection or transport in these locations?

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Classification of Epithelial Tissues
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Example of Simple Cuboidal Epithelium

• Sectional view of kidney tubules
• Why do some cells look as if they do not have a
  nucleus?

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Nonciliated Simple Columnar

• Unicellular glands goblet cells secrete mucus
• lubricate GI, respiratory, reproductive and
  urinary systems
• Microvilli fingerlike projections of cell
  membrane
• Describe the differences between cilia and
  microvilli in terms of both their structure and
  function. Are you likely to find them on the
  same tissue? Why or Why not?

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Example Nonciliated Simple Columnar Epithelium

• Section from small intestine
• The term brush border is often used to describe
  this tissue. What does it refer to?

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Ciliated Simple Columnar Epithelium

• Single layer rectangular cells with cilia
• Mucus from goblet cells moved along by cilia

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Example Ciliated Simple Columnar Epithelium

• Section of uterine tube
• What is another name for this organ?

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Stratified Squamous Epithelium

• Several cell layers thick
• Surface cells flat
• Keratinized surface cells dead and filled with
  keratin
• Example?
• Nonkeratinized no keratin in moist, living
  cells at apical surface
• Example ?

What is the primary function of this
epithelium? If this epithelium is a portion of a
mucus membrane, where does the mucus come from?
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Example of Stratified Squamous

• Section of vagina

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Stratified Cuboidal Epithelium

• Multilayered
• Surface cells cuboidal
• rare (only found in sweat gland ducts male
  urethra)

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Stratified Columnar Epithelium

• Multilayered
• Surface cells columnar
• Rare (very large ducts part of male urethra)

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Transitional Epithelium

• Multilayered
• Surface cells varying in shape from round to flat
  if stretched
• Lines hollow organs of the urinary tract that
  expand from within

List the expandable organs of the urinary tract.
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Pseudostratified Columnar

• Single cell layer
• All cells attach to basement membrane but not all
  reach free surface
• Nuclei at varying depths

Name one location where you would find this
epithelium. How would you describe its function?