We often hear good people refered to as having a big heart while smart people are often talked about as having a big brain, but this raises a question – what is the largest organ in the human body? First of all, neither the heart nor the brain can claim that title, although essential to a human being’s survival. This being said, the brain does in fact contribute to nearly 2% of a body’s weight while the heart can sometimes weight up to 1 kg.
Interestingly enough, the largest organ in the human body is actually the epidermis. The epidermis is a human body’s largest and fastest growing organ, yet we all refer to it as ‘skin’. Yes, your skin is actually an organ, the largest, fastest growing organ within your body actually. Not only is the skin responsible for keeping a human being’s internal organs safe, but it also provides thermal insulation from the weather outside.
Furthermore, the epidermis is responsible for keeping out germs and bacteria that could potentially harm your insides. The human skin consists of five layers: stratum basale, stratum spinosum, stratum granulosum, stratum licidum, and stratum corneum. Stratum basale is responsible for shielding the nerves that deal with light touch sensations, stratum spinosum contains various enzymes and immunologically active cells, stratum granulosum acts as a lipid barrier, stratum licidum is basically the ‘thick skin’ underneath the surface, while stratum corneum is the surface of the skin.
On average, the skin of a regular adult has a surface of 21 square feet and accounts for 6% to 10% of a human being’s weight. The epidermis is also avascular, meaning that it gets nourished almost entirely by diffused oxygen from the surrounding air. The main purpose of a person’s skin is to serve as a barrier against microbial pathogens, oxidant stress, and chemical compounds while providing mechanical resistance from the environment.
The human body has 78 organs out of which the skin, like we already established, is the largest. The second largest organ in a human body accounts for approximately 2.5% of a person’s weight, a bit more than the third largest organ which is the brain. The average weight of a human being’s brain is 1.263 grams and it accounts for a little more than 2% of a person’s body weight. Next come the lungs, which can weight about 1,090 grams, followed by the heart which can weight as much as 1 kg.
Our bodies, although it may not seem this way at first sight, are very advanced mechanisms, capable of sustaining tremendous amounts of abuse from our surrounding environment. Our internal organs are comprised of millions of cells that group together to perform the vital functions without which our bodies would shut down. While some internal organs can be replaced if necessary, a human being’s brain and skin are vital to a person’s survival and to our knowledge, have never been transplanted successfully from one human being to another.
Interesting facts about the skin:
- It renews itself every 28 days
- Goose bumps help retain a layer of warm air
- The thinnest layer of skin is around the eyes
- We have an average of 500 sweat glands on each 5 square centimeters of skin
- Our skin grows from being 1 mm thick at birth to around 2-3 mm as adults
- Skin contains keratin, a protein that can also be found in our nails and hair
- Our skin loses 30,000 to 40,000 dead skin cells from the surface almost every minute