Structure and Functions of the Liver in Human Body
The human body is made up of various organs, each performing vital functions to maintain overall health. When discussing organ size, scientists consider both external and internal organs by mass and surface area. Understanding which organ is the largest inside the human body—and the functions it carries out—helps us appreciate the complexity of our bodily systems.
The largest organ in the human body overall is the skin. The skin covers our entire exterior, making up about 16 percent of our total body mass, with a thickness of roughly 2 millimeters. Its main functions are to protect the body from environmental factors like germs and sun radiation, regulate temperature, sense the environment, and store fats and vitamins. For more on this topic, see Skin: Structure and Functions.
When we shift focus to internal, solid organs, the liver stands out as the largest. The liver weighs approximately 1.36 to 1.59 kilograms (about 3 to 3.5 pounds) in a healthy adult, making it larger than other internal organs such as the brain, lungs, heart, and kidneys.
Location and Structure of the Liver
The liver is found just beneath the rib cage and lungs, mainly in the upper right side of the abdomen. It is about the size of a football and has a reddish-brown color due to its rich blood supply. The liver consists of two main lobes and is connected to the digestive system via the bile ducts.
Key Functions of the Liver
The liver performs several essential roles that are crucial for survival:
- Filtering and removing harmful toxins from the blood
- Producing bile needed for digesting fats
- Creating proteins critical for blood plasma
- Storing excess glucose as glycogen, then converting it back when needed
- Helping regulate blood clotting
Largest and Major Internal Organs: Comparison Table
| Organ | Location | Average Adult Weight | Main Functions |
|---|---|---|---|
| Liver | Upper right abdomen | 1.36–1.59 kg | Metabolism, detoxification, protein synthesis, bile production |
| Brain | Skull cavity | 1.36 kg | Processing information, controlling body functions |
| Lungs (pair) | Thoracic cavity | ~1 kg | Oxygen exchange, expelling carbon dioxide |
| Heart | Between lungs | ~300 g | Pumping blood to the body |
| Kidneys (pair) | Lower back, below ribs | ~300 g each | Filtering blood, producing urine |
How Does the Liver Support Digestion and Metabolism?
The liver produces bile, a yellowish fluid essential for the digestion and absorption of fats. Bile is stored in the gallbladder and released into the small intestine during meals. The liver also helps process nutrients from food and stabilizes blood sugar by storing and releasing glucose as needed.
Examples for Understanding
- Example: After a carbohydrate-rich meal, the liver stores extra glucose as glycogen. If you skip a meal, it releases the stored glucose to keep your body’s energy steady.
- Example: When medicines or alcohol are consumed, the liver helps break down and remove these substances from the bloodstream.
Other Noteworthy Organs and Their Roles
- Brain: Weighs about 1.36 kg; controls thinking, sensations, and body functions. For more, visit Human Body Anatomy.
- Lungs: Can hold up to 6 liters of air; enable gas exchange during breathing. More at Human Lung.
- Heart: About 300 grams; circulates blood to every part of your body. See Human Heart.
- Kidneys: Small but dense; filter approximately 200 quarts of fluid a day, removing waste as urine. Explore Human Excretory System.
Special Note: The Interstitium
Recent studies suggest the interstitium—a network of fluid-filled spaces within connective tissue—could be the body's largest organ. However, this is still being debated. Until officially classified, skin and liver remain the largest external and internal organs, respectively.
Practice Questions
- Which is the largest internal solid organ in the human body?
- What main fluid does the liver produce for digestion?
- Where is the liver located in the body?
Vedantu Resources for Further Study
- Liver: Detailed Functions and Structure
- Human Digestive System Overview
- Digestive System Diagrams
- Human Body Anatomy
Conclusion
The liver is the largest internal solid organ in the human body, vital for metabolism, detoxification, and digestion. Its size and role distinguish it from all other organs inside the body. Learning about organ size and function helps students understand the importance of body systems for health and everyday life.
FAQs on Largest Internal Organ of the Human Body Explained
1. What is the largest internal organ of the human body?
The largest internal organ in the human body is the liver. It typically weighs about 1.2–1.5 kg in adults and is located in the upper right area of the abdomen. The liver is crucial for metabolism, digestion, detoxification, and storage of nutrients.
2. Which organ is called the largest gland in the body?
The liver is also the largest gland in the human body. It acts both as an organ and a gland because it produces and secretes bile, essential for fat digestion.
3. What is the main function of the liver?
The liver performs multiple vital functions, including:
- Metabolism of carbohydrates, proteins, and fats
- Production of bile for fat digestion
- Detoxification of blood
- Storage of vitamins and minerals
- Synthesis of plasma proteins and clotting factors
4. Is the skin the largest organ in the human body?
Yes, the skin is the largest organ overall in the human body. However, it is an external organ. The largest internal organ is the liver.
5. What is the second largest internal organ in the human body?
The brain is generally considered the second largest internal organ by weight, weighing approximately 1.25–1.4 kg in adults. The lungs, as a pair, also have a combined considerable mass, close to that of the brain.
6. What is bile and what is its role in digestion?
Bile is an alkaline fluid produced by the liver. Its main role is to emulsify fats in the small intestine, aiding in the digestion and absorption of dietary fats.
7. Where is the liver located in the human body?
The liver is located in the upper right quadrant of the abdomen, just below the diaphragm and above the stomach. It extends across the midline to the left upper abdomen.
8. What are some diseases associated with the liver?
Common diseases of the liver include:
- Hepatitis (inflammation)
- Cirrhosis (chronic damage and scarring)
- Fatty liver disease
- Liver cancer
- Jaundice (yellowing of skin due to excess bilirubin)
9. How does the liver help in blood glucose regulation?
The liver maintains blood glucose levels by:
- Converting excess glucose to glycogen for storage (glycogenesis)
- Breaking down glycogen to glucose when needed (glycogenolysis)
- Producing glucose from non-carbohydrate sources (gluconeogenesis) during fasting
10. What are the main storage functions of the liver?
The liver stores:
- Glycogen (for energy)
- Vitamins (A, D, B12)
- Minerals (iron, copper)
These resources are released as needed to maintain normal body function.
11. What is the difference between the largest organ, the largest gland, and the largest internal organ?
The largest organ overall is the skin (external).
The largest internal organ and largest gland is the liver. This distinction is important for exams:
- Skin: Largest organ (external)
- Liver: Largest internal organ and largest gland in the body
12. Why is understanding the liver’s structure and function important for NEET and board exams?
Mastery of liver anatomy and functions is vital for NEET, CBSE, and ICSE board exams because:
- It is a high-weightage topic in Human Physiology
- Understanding helps in solving MCQs on metabolism, digestion, and diseases
- It builds a foundation for advanced medical studies
