Editing Lymphatic system (section)

===Fat absorption===
[[File:Nutrient absorbtion to blood and lymph.png|thumb|280x280px|Nutrients in food are absorbed via [[Intestinal villus|intestinal vili]] (greatly enlarged in the picture) to blood and lymph. Long-chain [[fatty acid]]s (and other [[lipid]]s with similar fat solubility like some medicines) are absorbed to the lymph and move in it enveloped inside [[chylomicron]]s. They move via the thoracic duct of the lymphatic system and finally enter the blood via the left subclavian vein, thus bypassing the liver's [[First pass effect|first-pass metabolism]] completely.]]
[[Lymph vessel]]s called [[lacteal]]s are at the beginning of the [[gastrointestinal tract]], predominantly in the small intestine. While most other nutrients absorbed by the [[small intestine]] are passed on to the [[portal venous system]] to drain via the [[portal vein]] into the [[liver]] for processing, fats ([[lipids]]) are passed on to the lymphatic system to be transported to the blood circulation via the [[thoracic duct]]. (There are exceptions, for example [[medium-chain triglycerides]] are fatty acid esters of glycerol that passively diffuse from the GI tract to the portal system.) The enriched lymph originating in the lymphatics of the [[small intestine]] is called [[chyle]]. The nutrients that are released into the circulatory system are processed by the [[liver]], having passed through the systemic circulation.