Accessory Organs of Digestions

Pancreas, liver, gallbladder: food never passes through them directly, but they secrete enzymes/bile into the tract.
Pancreas exocrine function (acinar cells): bicarbonate (neutralizes acid) + digestive enzymes for all 3 macronutrients (amylase, lipase, proteases). Proteases secreted as zymogens, activated in the duodenum (enteropeptidase → trypsin → cascade).
Secretin (triggered by acid) → pancreatic bicarbonate. CCK (triggered by fats/amino acids) → pancreatic enzymes + gallbladder contraction.
Liver: produces bile continuously (not an enzyme — emulsifies fat), processes bilirubin (disrupted → jaundice), regulates blood glucose (glycogenesis/glycogenolysis/gluconeogenesis), synthesizes plasma proteins (albumin, clotting factors), converts ammonia → urea, detoxifies.
Gallbladder stores/concentrates bile — does NOT make bile or produce enzymes. CCK triggers contraction/release in response to dietary fat.
All 3 macronutrients finish digestion in the small intestine, but start in different places (carbs: mouth; proteins: stomach; lipids: small intestine, most dependent on accessory organs).

Acinar cells: Pancreatic exocrine cells that produce pancreatic juice (bicarbonate + digestive enzymes).
Zymogens: Inactive enzyme precursors (e.g., trypsinogen) that prevent an organ from digesting itself.
Bile salts: Components of bile that emulsify fat — mechanically break large fat droplets into smaller ones, not via enzymatic bond-breaking.
Bilirubin: Waste product from RBC breakdown, processed by the liver and excreted in bile; buildup causes jaundice.
Urea: Non-toxic molecule the liver converts ammonia into, for safe excretion by the kidneys.

Liver	Gallbladder
Produces bile continuously	Stores and concentrates bile (does NOT make it)
Processes bilirubin, regulates glucose, synthesizes plasma proteins, detoxifies	Releases bile into duodenum when CCK signals contraction (triggered by dietary fat)
Central metabolic/detox hub	Purely a reservoir — no enzyme production

Secretin	CCK
Triggered by acidic chyme	Triggered by fats/amino acids
Stimulates pancreatic bicarbonate secretion	Stimulates pancreatic enzyme secretion + gallbladder contraction

Bile is NOT an enzyme — it never breaks chemical bonds. It only emulsifies fat (mechanical action), increasing surface area for pancreatic lipase.
The gallbladder does not PRODUCE bile — only the liver does. The gallbladder is a storage/concentration reservoir only.
Pancreatic proteases are secreted as zymogens and activated by enteropeptidase (a brush-border enzyme) — NOT by the pancreas itself. This spatial separation prevents pancreatic self-digestion.

What are the 2 major components of pancreatic juice?

Does the gallbladder produce bile?

What causes jaundice?

How does bile aid fat digestion if it's not an enzyme?

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