What is the largest organ in the human body by surface area?
A.
Brain
B.
Heart
C.
Liver
D.
Skin
The correct answer and Explanation is :
The largest organ in the human body by surface area is D. Skin.
Explanation
The skin, also known as the integumentary system, is the body’s largest organ in terms of surface area. It covers and protects the entire external surface of the body and serves as a barrier to the external environment. On average, the adult human skin has a surface area of approximately 1.5 to 2 square meters (16 to 22 square feet).
Functions of the Skin:
- Protection: The skin acts as a protective barrier against physical damage, pathogens, and harmful substances. It also prevents dehydration by minimizing water loss.
- Temperature Regulation: Through the processes of sweating and blood vessel dilation or constriction, the skin helps regulate body temperature.
- Sensory Perception: It contains a variety of sensory receptors that detect touch, pain, pressure, and temperature, which help in interacting with the environment.
- Synthesis of Vitamin D: When exposed to sunlight, the skin synthesizes vitamin D, which is crucial for calcium absorption and bone health.
- Excretion: The skin excretes small amounts of waste products through sweat.
Comparison with Other Organs:
- Brain: While the brain is a vital organ, its surface area is much smaller compared to the skin. It is well-protected inside the skull and does not cover as much surface area as the skin.
- Heart: The heart, an essential organ for pumping blood throughout the body, is relatively small compared to the skin. It is also located within the thoracic cavity and does not have a large surface area.
- Liver: The liver is a large organ with many crucial functions such as detoxification and metabolism, but it is internal and does not cover as much surface area as the skin.
Overall, the skin’s extensive surface area is critical for its multifaceted roles in protecting and maintaining the body’s internal environment.