Small Intestine

  • The mammalian small intestine is highly specialized for digestion and especially absorbtion
  • Villi and microvilli increase absorbtive surface of small intestine
  • Each villus contains a lacteal which is a terminal brach of the lymphatic system and is a terminal brach of the lymphatic system and is an important route for reabsorbtion of lipids and water.
  • The surface of microvilli is covered with a meshwork of mucopolyaccharide and glycoprotein filaments, the glycocalyx
  • This surface coat is extremely resistant to proteolytic and mucolytic agents, hence forms a protective surface.
  • Many of important digestive enymes are absorbed into the glycocalyx meshwork, pancreatic amylase, disaccharases and dipeptidases.
  • There are four basit mechanism for uptake of nutriends from the gut lumen and glycocalyx layer cytoplasm of the epithelial cells.
  • Passive diffusion, Faciliated diffusion, Active transport, Pinocytosis