What are the special lymphatic capillaries in the small intestine called?

Lacteals are specialized lymphatic capillaries found in the small intestine, specifically within the villa which are small finger-like projections that extend into the intestinal lumen. The primary function of lacteals is to absorb dietary fats and fat-soluble vitamins from the digestive tract. These capillaries are uniquely structured to accommodate the uptake of large lipid molecules, which become emulsified during digestion.

When fats are consumed, they are broken down into fatty acids and monoglycerides, which then enter the lacteals and are transported as part of a fluid called chyle. This is a milky fluid that contains lymph mixed with emulsified fats. Through the action of the lymphatic system, chyle is eventually delivered into the bloodstream, allowing the body to utilize these nutrients effectively.

This specialized role of lacteals distinguishes them from lymph nodes, chyle ducts, and intestinal trunks, which play different roles in the lymphatic system. Lymph nodes function primarily in filtering lymphatic fluid and housing immune cells, while chyle ducts are vessels that transport chyle, and intestinal trunks are larger lymphatic vessels that collect lymph from the intestines.