What is the primary function of the liver in the human body?

Step 1: Analyze the question The question asks for the primary function of the liver, so we need the option that best describes its main role.

Step 2: Explain the concept The liver is the largest internal organ and acts as the body's chemical processing plant. Its major functions include:

• Detoxification: it breaks down poisons, alcohol, drugs and ammonia (converting ammonia to urea).
• Metabolism of nutrients: it regulates blood glucose by converting excess glucose to glycogen, processes fats and amino acids (deamination), and stores vitamins and minerals such as A, D, B12 and iron.
• Bile production: bile helps emulsify fats.
• Production of plasma proteins: albumin and clotting factors such as fibrinogen and prothrombin.
• Breakdown of old red blood cells.

Step 3: Check each option

• A. Regulation of body temperature: The liver generates some heat as a by-product of its activity, but temperature regulation is controlled mainly by the hypothalamus and the skin. Not primary.
• B. Regulation of blood pressure: This is handled mainly by the heart, blood vessels, and kidneys. Not the liver.
• C. Production of hormones: The liver makes a few hormone-related substances (such as angiotensinogen and IGF-1), but hormone production is the main job of the endocrine glands such as the pituitary, thyroid, and adrenal glands. Not primary.
• D. Detoxification and metabolism of nutrients and drugs: This covers the liver's core roles. Correct.

Step 4: Answer The correct option is D.

Exam tip: Link the liver with "Detoxification, Deamination, Digestion aid (bile)". If a JAMB question asks about the liver, think of processing and detoxifying blood coming from the intestines through the hepatic portal vein.