What is the Origin of Lymphatic System Absorption?

This term is rooted in gastrointestinal physiology and pharmacology, dating back to the recognition that not all absorbed nutrients enter the portal vein. The distinct route for lipid-soluble substances was identified by tracking chylomicrons, the lipoprotein particles formed in the enterocytes.

What is the Mechanism of Lymphatic System Absorption?

The mechanism begins with the formation of chylomicrons within the intestinal enterocytes from absorbed dietary fats. These large lipoprotein particles are too substantial to enter the blood capillaries directly. Instead, they are exocytosed into the interstitial space and then readily diffuse into the porous, initial lymphatic capillaries (lacteals). This lymphatic transport allows the essential lipids and certain therapeutic agents to reach the systemic circulation and peripheral tissues before being processed by the liver.

Lymphatic System Absorption ∞ Area

Lymphatic System Absorption

Meaning

Lymphatic system absorption specifically refers to the process by which certain substances, predominantly long-chain fatty acids, fat-soluble vitamins (A, D, E, K), and some large peptide or lipophilic drug molecules, are taken up from the intestinal lumen into the specialized lymphatic vessels called lacteals. This pathway bypasses the initial circulation through the liver (first-pass metabolism) and allows for systemic distribution of these essential lipids and therapeutics. This mechanism is particularly relevant in the pharmacokinetics of lipophilic hormonal agents.