What does chylomicron mean?
A chylomicron is one of the largest class of lipoprotein particles in human blood, produced by the cells lining the small intestine after a meal containing fat. Because these newly absorbed fats are too bulky to pass directly into blood capillaries, they are packaged instead into chylomicrons, which travel through the lymphatic system before entering the bloodstream. There they deliver triglycerides, cholesterol, and fat-soluble vitamins such as A, D, E, and K to tissues, gradually shrinking into smaller particles known as chylomicron remnants that are cleared by the liver. Chylomicron levels normally rise after eating and fall during fasting, which is why blood lipid tests are typically done fasting. The term derives from Greek roots meaning juice and small, reflecting both the milky fluid in which the particles were first observed and their microscopic size.
nounA microscopic lipoprotein particle formed in the small intestine that transports dietary fats and fat-soluble vitamins through the lymph and bloodstream to the tissues.
- A microscopic lipoprotein particle assembled by intestinal cells after a fatty meal to transport dietary triglycerides, cholesterol, and fat-soluble vitamins via the lymph into the bloodstream.
"After a rich meal, chylomicrons flood the bloodstream carrying absorbed triglycerides to the body's cells."
"Levels of chylomicrons in the plasma peak a few hours after a high-fat meal."
"Because patients with abetalipoproteinaemia cannot form chylomicrons, dietary fats are poorly absorbed."
The classical plural 'chylomicra' is preferred in formal scientific writing; the anglicized 'chylomicrons' is common and acceptable in everyday medical usage.
"Chylomicra were clearly visible in the patient's plasma sample after the fat-tolerance test."
Every creamy meal you eat travels your bloodstream as particles so large they can't enter blood vessels directly — they must first detour through your lymphatic system.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of chylomicron
The word 'chylomicron' was coined in the early twentieth century from two Greek-derived elements: 'chylos' (χυλός), meaning the milky intestinal juice or 'chyle' long recognized in anatomy, and 'mikros' via the diminutive suffix '-on', echoing the established term 'micron'. It thus literally means a tiny particle of chyle, named when such droplets were seen under the microscope in lymph after fatty meals. Its relatives include the anatomical terms 'chyle', 'chylous', and 'chylothorax'.
How chylomicron is actually used
Strictly a technical term of physiology, biochemistry, and medicine; it appears almost exclusively in scientific literature, clinical discussion, and advanced education rather than everyday conversation. The standard plural is 'chylomicra', though 'chylomicrons' is also widely accepted in modern usage.
Easily confused with chylomicron
Chyle is the milky bodily fluid that carries the chylomicrons, whereas a chylomicron is one of the individual fat-transporting particles within it.
A micron is simply a unit of length equal to one millionth of a metre, while a chylomicron is a biological particle whose name merely borrows the Greek word for 'small'.