Which circulation is responsible for the majority of bile reabsorption?

The enterohepatic circulation is the pathway primarily responsible for the majority of bile acid reabsorption. This system involves the cycling of bile acids from the liver to the intestinal tract and back to the liver. After bile is secreted into the intestine, bile acids aid in the digestion and absorption of fats.

A significant portion of these bile acids is then reabsorbed in the ileum, the last segment of the small intestine, and transported back to the liver via the portal circulation. This reabsorption process is crucial for maintaining bile acid pool size and is an efficient mechanism that conserves these valuable substances.

By reabsorbing bile acids, the liver can reduce the need to synthesize new bile acids, thus conserving energy and resources. This enterohepatic cycle not only reclaims bile acids but also regulates their levels within the body, which is fundamental to digestion and fat metabolism.

In contrast, systemic circulation is involved in transporting blood throughout the body, while lymphatic circulation primarily deals with the transport of lipids and immune cells. The portal circulation, while important for the transport of reabsorbed bile acids back to the liver, does not encompass the complete cycle of bile acid utilization as effectively as enterohepatic circulation.