Digestion and Absorption of Lipids
Start with the big picture
Lingual and gastric lipases initiate triglyceride hydrolysis; in the duodenum, CCK promotes bile release and pancreatic enzyme secretion, while secretin supports an appropriate pH through bicarbonate secretion. Bile salts emulsify fats and form mixed micelles that carry digestion products to the intestinal brush border. Pancreatic lipase with colipase, cholesterol esterase, and phospholipase A₂ act on different lipid substrates. Enterocytes absorb lipid products, re-esterify many of them, and package them with apoB-48 into chylomicrons for lymphatic transport. Glycerol and short- or medium-chain fatty acids can instead enter portal blood. The lesson also connects bile acid recovery in the terminal ileum and disruptions in digestion or absorption with steatorrhea.
What you'll learn
- Trace lipid digestion from oral and gastric lipases through the major duodenal phase.
- Describe how CCK, secretin, bile salts, and pancreatic enzymes support lipid digestion.
- Explain micelle transport and lipid entry into intestinal enterocytes.
- Outline re-esterification, chylomicron assembly, and routes of lipid transport.
- Identify bile acid recovery and mechanisms associated with steatorrhea.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
