GI: Accessory organs

Question 1

Exocrine secretions of pancreas and stimulus for secretions

Answer 1

• Bicarbonate (from low pH in duodenum from stomach contents, secretin released and acts on ducts)
• Enzymes (CCk released to products of digestion and releases enzymes)

Question 2

Functions of the liver in macromolecule metabolism

Answer 2

• Carb: regulates blood sugar
• Protein: Dietary proteins -> a.a, synthesizes plasma proteins and ammonia -> urea
• Lipid: Bile, processing fatty acids/ triglycerides, synthesizes lipoproteins, cholestrol and phospholipids.

Question 3

Sinusoids

Answer 3

Special liver blood vessels with fenestrated endothelium.

Question 4

Bile composition

Answer 4

Bile salts, bile pigments and cholesterol

Question 5

Where are bile salts from?

Answer 5

Made from new cholesterol or recovered from portal blood (95% return)

Question 6

Stimulus for bile release

Answer 6

Fats -> CCK-> gallbladder contraction -> bile released

Question 7

How does bile help break down fats?

Answer 7

• Amphipathic (hydrophillic and hydrophobic)
• Forms micelle, delivers to brush border and contents diffuse through cell
• Packaged by golgi and transported through lymphatic