Lecture on the Liver

Introduction

• The liver is a key organ in the digestive system.
• It is unique in its ability to regenerate; a small portion can grow into a full organ.
• Main functions include metabolism, storage of nutrients, detoxification, and bile synthesis.

Metabolic Functions

• Responsible for breaking down nutrients (catabolism) and creating larger molecules (anabolism).
• Manages the breakdown and creation of food substances.

Storage Functions

• Stores nutrients when they are not being broken down or created.
• Stores carbohydrates and fats in three forms:
  • Glycogen: A polysaccharide formed from monosaccharides.
  • Lipoproteins: Combination of lipid (fat) and protein.
  • Triglycerides: Fat stored in forms obtained from food.
• Proteins are processed but not stored; turned into albumins and released into the bloodstream.

Detoxification

• Detoxifies harmful substances to prevent damage to the organism.
• Uses enzymes called cytochromes P450, which can react with various substrates.
• Detoxification can reduce the effectiveness of drugs, requiring careful dosage by doctors.

Bile Synthesis

• Essential for the absorption of fats in the intestines.
• Discussed in more detail in a separate lecture.

Blood Supply to the Liver

• Unique as it receives blood from two sources:
  • Portal Vein: Brings nutrient-rich blood from the gastrointestinal system.
  • Hepatic Artery: Supplies oxygen-rich blood.
• Blood is carried away from the liver via the hepatic vein, which returns to the heart for oxygenation and nutrient supply.

Summary

• The liver's multifaceted role includes processing, storing, detoxifying, and synthesizing substances.
• Essential for maintaining homeostasis and overall health.
• Further discussions on bile and more specific functions to follow in future lectures.