The Liver: Anatomy, Functions, and Disorders, Structure, Function, and Clinical Significance, Key Functions and Diseases

Liver

Introduction

The liver is the largest internal organ and the largest gland in the human body. It plays a crucial role in metabolism, digestion, detoxification, and storage of nutrients.

📍 Location: The liver is located in the right upper quadrant (RUQ) of the abdomen, just below the diaphragm, and protected by the ribcage.

📏 Size & Weight:

• Adult liver weighs 1.2 – 1.5 kg.

• It measures about 15 – 17 cm in width.

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Anatomy of the Liver

🟠 Lobes of the Liver:
The liver is divided into four lobes:

1. Right lobe – Largest lobe.
2. Left lobe – Smaller than the right lobe.
3. Caudate lobe – Near the inferior vena cava.
4. Quadrate lobe – Near the gallbladder.

🔗 Ligaments of the Liver:

• Falciform ligament – Connects liver to the anterior abdominal wall.
• Round ligament – Remnant of the umbilical vein.
• Coronary ligament – Attaches liver to the diaphragm.

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Blood Supply of the Liver

The liver has a dual blood supply:

1. Hepatic artery (25%) – Brings oxygenated blood from the aorta.
2. Hepatic portal vein (75%) – Brings nutrient-rich blood from the gastrointestinal tract.

🩸Venous Drainage: Blood leaves the liver via hepatic veins into the inferior vena cava (IVC).

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Histology of the Liver

The liver is made up of functional units called lobules, which contain:
✔ Hepatocytes – Main liver cells responsible for metabolism.
✔ Sinusoids – Blood-filled spaces for filtration.
✔ Kupffer cells – Macrophages that remove debris and old RBCs.
✔ Bile canaliculi – Transport bile to bile ducts.

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Physiology of the Liver

🛠 Functions of the Liver:

1️⃣ Metabolism

🔹 Carbohydrate Metabolism – Regulates blood glucose levels by storing and releasing glycogen.
🔹 Lipid Metabolism – Synthesizes cholesterol, lipoproteins, and triglycerides.
🔹 Protein Metabolism – Produces plasma proteins like albumin and clotting factors.

2️⃣ Detoxification

☣ Removes toxins like drugs, alcohol, and ammonia (converted to urea).

3️⃣ Bile Production & Excretion

🟢 Produces bile (500–1000 mL/day) for fat digestion.
🔗 Bile is stored in the gallbladder and released into the duodenum.

4️⃣ Storage Function

📦 Stores vitamins (A, D, E, K, B12), iron, and glycogen.

5️⃣ Immune Function

🦠 Kupffer cells help in defense by removing bacteria and dead cells.

6️⃣ Hormone Regulation

⚖ Modifies hormones like insulin, estrogen, and cortisol.

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Common Liver Disorders

❌ Hepatitis – Inflammation of the liver caused by viruses (Hepatitis A, B, C).
❌ Cirrhosis – Chronic liver damage leading to scarring and liver failure.
❌ Fatty Liver Disease – Accumulation of fat in the liver due to alcohol or obesity.
❌ Liver Cancer – Malignant tumor (hepatocellular carcinoma).
❌ Jaundice – Yellowing of skin due to bilirubin accumulation.

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Conclusion

The liver is a vital organ responsible for metabolism, detoxification, digestion, and nutrient storage. Maintaining liver health through a balanced diet, hydration, and avoiding excessive alcohol or toxins is crucial. 💚