Lecture on the Liver in the GI Tract

Overview of the Liver

• Described as a 'cool' organ due to its ability to regenerate and sustain life after partial transplant.

Main Functions of the Liver

Metabolism

• Catabolism: Breakdown of nutrients.
• Anabolism: Building up of larger macromolecules.

Storage

• Stores nutrients when not being metabolized.
• Stores carbohydrates and fats:
  • As glycogen (polysaccharide).
  • As lipoproteins (complex of fat and proteins).
  • As triglycerides (form of fat from food).
• Proteins are processed into molecules like albumin and released into the bloodstream.

Detoxification

• Cytochrome P450 enzymes: Responsible for modifying toxins to prevent harm.
  • These enzymes react with a variety of substrates, not specific like other enzymes.
  • Can affect drug efficacy by breaking down medications perceived as toxins.
• Drug dosages are adjusted to counteract detoxification effects.

Bile Production

• Essential for the absorption of fats from food.
• Details on bile production will be covered in a subsequent video.

Blood Supply to the Liver

Incoming Blood Supply

• Portal Vein: Brings nutrient-rich blood from the intestinal tract to the liver.
• Proper Hepatic Artery: Supplies oxygen-rich blood via arterial circulation.

Outgoing Blood Supply

• Hepatic Vein: Carries nutrient- and oxygen-poor blood away from the liver back to the heart.

Bile Output

• Common Hepatic Duct: Transports bile out of the liver.
• Further specifics on bile output will be discussed later.