Lecture 5

• Digestive Accessory Organs

  • 1. Pancreas
  • 2. Liver
  • 3. Gallbladder 
• Pancreas


  Secretes enzymes that promote the breakdown of proteins, carbohydrates and lipids
• Bicarbonate release


  Neutralize the acidic chyme entering from the stomach
• Enterokinase- Proteins


  Converts trypsinogen into its active form trypsin
• Trypsin- Proteins


  Breaks down long chains polypeptides into shorter chains
• Erepsins (peptidases)


  Complete protein digestion by breaking short chain peptides into amino acids
• Amylase- Carbohydrates


  Continues the digestion of carbohydrates
• Lipases- Fats


  Break down fats into fatty acids and glycerol; act on phospholipids
• Liver 

  • Is the largest internal organ of the body
  • Liver produces bile which helps speed up fat digestion in the small intestine
  • Bile will break apart fat globules into smaller droplets (physical digestion)
  • Bile is not an enzyme!! It is produced by the liver and stored in the gallbladder.
  • When fat is eaten the gallbladder will squeeze the Bile out and it is sent to the small intestine.
  • The liver will also help detoxify your blood (alcohol, toxins) 
• Function of the Liver

  1. Synthesis produces bile salts which break down fats (bile is stored in the gallbladder)
  2. Storage - converts glucose into glycogen (for storage in the liver and muscles) and vice versa to maintain blood sugar levels

  • Stores vitamins 

  3. Detox converts harmful components into less harmful substances (ex. alcohol) 

  
  

  4. Breakdown removes the nitrogen group from amino acids (toxic), forming urea
• Gallbladder

  • Located under the liver
  • Stores Bile 
  • Bile emulsifies fat (breaks it down into smaller fat globules)
• Problems of the Digestive System:

  1. Acid Reflux & HeartBurn

  • The cardiac sphincter does not close completely thus allowing acid from the stomach to enter your esophagus.
  • Causes a burning sensation in the lower throat. 
• Problems of the Digestive System:

  2. Stomach Ulcers

  • The bacteria H.pylori is able to live in the stomach and will burrow its way through your stomach mucus. It will then prevent your rugae from making mucus in that area.
  • When your stomach lining is exposed to strong stomach acid it causes an ulcer. 
• Problems of the Digestive System

  3. Gallstones

  • Bile can form larger crystals in your gallbladder (gallstones) which can block the bile duct and impair fat digestion i.e. pain
• Problems of the Digestive System

  4. Jaundice 

  • Yellowish color of skin and other tissues because the collection of bile pigments stuck in blood when not removed in feces i.e. obstruction of bile duct 
• Problems of the Digestive System

  5. Cirrhosis

  • When the liver has been damaged and is unable to make harmful chemicals soluble in dissolve in blood or eliminate through the urine i.e. detoxify the body.