Microscopic Structure of the GI Tract

• Interior space of GI tract


  lumen
• GI tract wall consists offour layers

  mucosa, submucosa, muscularis, and serosa
• Mucosa


  innermost layer; epithelial tissue, lamina propria, muscularis mucosae
• Submucosa


  connective tissue with blood vessels, lymphatics, and nerves
• Muscularis

  longitudinal and circular layers of smooth muscle
• Serosa


  outermost layer; thin layer of connective tissue