Frog Biliary System: Bile Production and Fat Digestion

In frogs, as in vertebrates:

• Liver: Produces bile continuously.
• Gallbladder: Stores and concentrates bile (greenish, biliverdin-rich).
• Bile Duct (Cystic + Common): Transports bile to duodenum.

Process

1. Food enters stomach → chemical/mechanical digestion.
2. Chyme enters duodenum → stimulates CCK release.
3. CCK contracts gallbladder → bile ejected into duodenum.
4. Bile salts emulsify fats → increased surface area for pancreatic lipase.
5. Lipase hydrolyzes triglycerides → fatty acids + monoglycerides → micellar absorption.

Comparative Note

Frog anatomy is a classic vertebrate model. Bile composition similar (bile salts, bilirubin, cholesterol, phospholipids). No cystic duct in some species; gallbladder empties directly via hepatic duct.