Bile salts (bile acids)They coat fat and break it into small droplets.
Emulsion dropletsSmall fat droplets, each coated with bile salts.
Pancreatic lipaseThe enzyme that cuts fat into fatty acids and monoglycerides.
MicelleA tiny cluster of bile salts carrying digested fat.
Fatty acids and monoglyceridesThe products of fat digestion. They diffuse into the cell.
In the cell and after 8
Brush border (microvilli)The fringe of microvilli on top of the cell.
Enterocyte (absorptive cell)The absorptive cell that lines the small intestine.
Smooth endoplasmic reticulumHere fatty acids and monoglycerides are rebuilt into triglycerides.
Golgi apparatusIt packs the triglycerides into chylomicrons.
ChylomicronA fat-carrying particle built inside the cell.
ExocytosisA vesicle opens at the cell's base and lets the chylomicron out.
LactealThe lymph vessel of the villus. Chylomicrons enter it.
Blood capillarySugars and amino acids enter the blood here; chylomicrons do not.
How this list was compiled: Every name and every step checked on 2026-10-01 in both of these. (1) A university physiology textbook online, Absorption of Lipids in the Small Intestine, https://vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_lipids.html : bile acids break large droplets into smaller ones (emulsification); pancreatic lipase yields monoglyceride and fatty acids; micelles carry them to the brush border of the enterocyte; inside the cell they are made into triglyceride in the endoplasmic reticulum, packaged into chylomicrons in the Golgi and released by exocytosis at the base of the cell; chylomicrons enter the central lacteal and not capillary blood. (2) Wikipedia, text only: Chylomicron, Micelle, Bile acid, Enterocyte, Lacteal, Intestinal villus, Lipid metabolism and Digestion, https://en.wikipedia.org/wiki/Chylomicron and https://en.wikipedia.org/wiki/Enterocyte : the same steps, with the smooth endoplasmic reticulum named as the place where triglycerides are re-formed, and villus capillaries collecting amino acids and simple sugars. No OpenStax page was read. Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work
How it works
This lipid absorption diagram follows fat from one large droplet in the intestine to a lacteal, so you can label the steps of lipid absorption in order.
Read the full guide
In the intestine
Fat arrives as large droplets. Bile salts coat them and break them into the small droplets of an emulsion. Pancreatic lipase cuts the triglycerides into fatty acids and monoglycerides. These gather with bile salts in micelles, which carry them to the brush border.
Inside the cell and out
Fatty acids and monoglycerides diffuse into the absorptive cell. In the smooth endoplasmic reticulum they are rebuilt into triglycerides. The Golgi apparatus packs these into chylomicrons, and vesicles release them at the base of the cell by exocytosis. They enter a lacteal, not a blood capillary.
Follow the arrows: they give the order of the steps.
The quiz accepts bile acids, microvilli, absorptive cell and smooth ER.
Questions and answers
What are the steps of lipid absorption?
Bile salts break fat into small droplets. Pancreatic lipase digests them to fatty acids and monoglycerides, which micelles carry to the absorptive cell. The cell rebuilds triglycerides, packs them into chylomicrons and releases them into a lacteal.
What is the difference between a micelle and a chylomicron?
A micelle forms in the intestine, outside the cell: bile salts around fatty acids and monoglycerides. A chylomicron is built inside the cell from rebuilt triglycerides and leaves through the base of the cell.
Where do chylomicrons go after they leave the cell?
Into the lacteal, the lymph vessel of the villus. Lymph that carries chylomicrons is called chyle. Sugars and amino acids take another route, into the blood capillaries.
What does bile do to fat?
Bile salts coat large fat droplets and break them into smaller ones, which is called emulsification. Bile salts also form the micelles that carry digested fat to the cell.