Fat handling

emulsification with cholic acid and chenochdeoxycholic acid

micelles

  • formed by bile salts
  • 3-6 nm diameter
  • fat-soluble sterol group + water-soluble polar group (projecting outward)
  • transport medium for fatty acids and monoglycerides to brush border

chylomicrons

  • formed of triglycerides - 0.08-0.6 micron
  • contains cholesterol, phospholipids, apoprotein B
  • exit cell via exocytosis
  • transported through thoracic duct
  • t1/2 <1h
  • it's how fat soluble vitamins get absorbed from intestinal lumen

transport into organs

  • adipose tisuse, skeletal muscle and heart - synthesise lipoprotein lipase - hydrolyzes the triglycerides of chylomicrons as they come in contact with the endothelial wall, thus releasing fatty acids and glycerol

Guyton and Hall