Largest Organ in the Human Body – Explained

The human body contains numerous organs, each playing unique roles in keeping us alive and healthy. Some organs are highly visible from the outside, while others remain hidden inside. In total, we have around 78 to 80 organs that form different organ systems, such as the digestive system, respiratory system, and nervous system. Understanding the size, structure, and functions of each organ gives us a fascinating overview of how our body works.

What is the Biggest Organ in the Human Body?

The skin is universally recognised as the biggest organ in the human body. It serves as a protective covering for our entire body and performs many critical functions such as preventing water loss, regulating body temperature, protecting against pathogens, and sensing touch, pressure, and pain. Although it varies slightly from person to person, human skin generally covers an area of about 20 square feet and makes up roughly 16% of our total body mass.

Second Largest Organ in the Human Body

After the skin, the second largest organ in the body is the liver. Besides being the second biggest organ, it is also the largest gland in human body. The liver is found in the upper right portion of the abdomen. It weighs about 1.3 to 1.5 kilograms on average in adults and plays a central role in multiple bodily functions, including detoxification, protein synthesis, and digestion.

Top 10 Largest Organs

When ranking organs by aspects such as weight, size, and overall function, the top 10 largest organ in human body can be listed as follows:

1. Skin

2. Liver

3. Brain

4. Lungs

5. Heart

6. Kidneys

7. Spleen

8. Pancreas

9. Thyroid

10. Joints (often considered collectively as an organ system)

Below, we will explore some important details about these organs.

Exploring Each Organ

1. Skin

• Location: Entire outer covering of the body

• Key Features:

• Acts as the first line of defence against external factors

• Prevents water loss, regulates temperature, and synthesises Vitamin D

• Houses sensory receptors to detect touch, heat, cold, and pressure

2. Liver (Largest Organ in Human Body After Skin)

• Location: Upper right part of the abdomen

• Key Features:

• Largest gland in human body and the second largest organ in the body

• Filters toxins from the blood, synthesises plasma proteins (like albumin)

• Produces bile for fat digestion and stores extra glucose in the form of glycogen

3. Brain

• Location: Within the skull (cranial cavity)

• Key Features:

• Weighs about 1.3 to 1.4 kilograms

• Controls all voluntary and involuntary functions

• Responsible for cognition, memory, emotion, and sensory processing

4. Lungs

• Location: Chest cavity (thoracic cavity)

• Key Features:

• Pair of spongy organs that facilitate gas exchange (oxygen in, carbon dioxide out)

• Can hold 4–6 litres of air

• The total length of airways in both lungs is around 2400 kilometres

5. Heart

• Location: Between the lungs in the middle compartment of the chest

• Key Features:

• Pumps blood to all parts of the body

• Roughly the size of a closed fist

• Beats around 100,000 times a day

6. Kidneys

• Location: Rear wall of the abdominal cavity, one on each side of the spine

• Key Features:

• Filter blood to remove waste and extra water, forming urine

• Help maintain electrolyte balance and blood pressure

7. Spleen

• Location: Under the rib cage, on the left side of the abdomen

• Key Features:

• Filters old and damaged red blood cells

• Stores platelets and white blood cells

• Plays a role in immune response

8. Pancreas

• Location: Behind the stomach in the upper left abdomen

• Key Features:

• Produces digestive enzymes

• Secretes insulin and glucagon to control blood sugar

9. Thyroid

• Location: Front of the neck

• Key Features:

• Butterfly-shaped gland regulating metabolism

• Secretes hormones that influence growth, development, and body temperature

10. Joints

• Location: Where two or more bones meet (throughout the body)

• Key Features:

• Enable smooth movement and flexibility

• Include different types: ball-and-socket, hinge, pivot, etc.

Additional Interesting Facts

• Smallest organ in human body: The pineal gland, deep inside the brain, often takes this title. It is crucial for regulating sleep patterns by secreting the hormone melatonin.

• Longest bone in the body: The femur (thigh bone) is not only the longest but also the strongest.

• Softest and lightest bone: The stapes in the middle ear.

• Hardest bone to break: The femur, again due to its thickness and strength.

• Weakest muscle: The strap muscles in the front of the neck are considered to be among the weakest, responsible mainly for supporting movements in the neck region.

Quick Quizzes

1. Which organ is considered the largest gland in the human body?
A. Pancreas
B. Liver
C. Thyroid
D. Skin
Answer: B. Liver

2. Which is the smallest organ in human body?
A. Heart
B. Pineal gland
C. Brain
D. Kidney
Answer: B. Pineal gland

3. Which of the following is the longest and strongest bone in the human body?
A. Stapes
B. Femur
C. Humerus
D. Radius
Answer: B. Femur

Related Topics

• Human Digestive System

• Human Respiratory System

• Human Skeletal System

• Excretory System