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🟡 Bile Acid Enterohepatic Circulation

Explore how the liver, gallbladder, and small intestine recycle bile acids up to several times per meal, and how a feedback loop through the nuclear receptor FXR links reabsorption to cholesterol-based synthesis.

Medicine & Biophysics3DModerate60 FPS

The simulator demonstrates the complete enterohepatic circulation loop: hepatic synthesis of bile acids from cholesterol via CYP7A1, gallbladder storage and concentration between meals, CCK-triggered release and fat emulsification after a meal, terminal ileum reabsorption at roughly ninety-five percent efficiency, portal vein return to the liver, and the FXR-mediated negative feedback loop that adjusts synthesis rate based on how much bile acid returns.

🔬 What It Demonstrates

🎮 How to Use

Start a simulated meal to trigger CCK release and watch the gallbladder contract, releasing concentrated bile into the duodenum to emulsify fat. Advance through digestion to see bile acids travel to the terminal ileum, where most are reabsorbed and routed back to the liver through the portal vein. Toggle a bile acid sequestrant or simulate ileal resection to interrupt reabsorption, then observe how reduced FXR activation drives up CYP7A1 activity and cholesterol consumption as the liver compensates.

💡 Did You Know?

The body's entire bile acid pool is only a few grams, yet because it can recycle several times during a single fatty meal, this small pool delivers far more total emulsifying capacity than its size alone would suggest, all thanks to the efficiency of the terminal ileum's dedicated reabsorption transporter.

⚙ Under the hood

physiologydigestionlivergallbladdercholesterolmetabolismendocrinology

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install