Small Intestine

• What is the LONGEST ORGAN of the alimentary canal?

  Small intestine
• Small intestine: responsible for most of the DIGESTION and nutrient ABSORPTION.
• What are the 3 main regions of the small intestine?

  Duodenum, jejunum, and ileum
• Duodenum: 1st part of the small intestine; SHORTEST region
• Jejunum: Region after duodenum; means EMPTY (such as when found in death)
• Ileum: Final and LONGEST region; joins the large intestine at the ILEAL ORIFICE.
• What are the 3 things that increase the surface area of the small intestine?

  circular folds, villi, and microvilli
• circular folds: DEEP RIDGE in mucosa and submucosa; increases absorption.
• Villi: FINGERLIKE projections of mucosa
• Microvilli: PROJECTIONS in apical membrane of absorptive cells