DIGESTION

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DIGESTION

• The structure of the small intestine

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The structure of the small intestine

• The ileum is well adapted for absorption
• It is very long about 6m in adults
• The internal lining is greatly folded giving a
  much greater surface area.
• On the folds are numerous finger-like projections
  called villi
• The epithelial cell have microscopic projections
  called microvilli

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The structure of the small intestine
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The structure of the small intestine

• Simple sugars, amino acids, salts and vitamins
  that have been absorbed pass out of the
  epithelial cells into a blood capillary inside
  the villus
• Blood travels from here to the liver via the
  hepatic portal vein
• The products of lipid digestion, the
  triglycerides, enter the lacteal in the villus

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The structure of the small intestine
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The structure of the small intestine

• You need to learn the details of the structures
  of the small intestine wall as shown in your
  hand-out!