Millions of finger-like projections, each covered in microvilli, giving the small intestine a huge surface for absorbing nutrients.
How it works, step by step
Brush-border enzymes finish digesting sugars and small peptides.
Sugars and amino acids cross into capillaries in each villus.
Fats enter a central lymph vessel called a lacteal.
Blood from the intestine flows first to the liver.
Evidence & sources
The small intestine's lining is folded into villi and microvilli, which greatly increase the surface available for absorption. Evidence: established. Known: Basic anatomy and physiology. Unknown: — Source: NCBI Bookshelf (StatPearls), Physiology, Small Bowel (Current revision).