You might be surprised, but the heaviest organ in the human body is the skin, which makes sense as it is also the largest organ in the body.
There are around 60 organs in the body, with each one performs specialized tasks. They aren’t all internal like the heart or the brain. Others are found on the outside. While some of them can be considered as vital than other organs, almost all organs are required for the human body to function optimally.
Among them all, the skin is the heaviest and largest organ. Adults carry about 8-10 pounds of skin with an average area of around 22 square meters. It accounts for 6% to 10% of our body weight, toppling the liver, which holds 2.5% of our mass.
An average-sized man sheds about 600,000 particles of skin each hour, which weighs around 680 grams per year. With that, one will have lost almost 105 pounds of skin by the age of 70, accounting for about two-thirds of a typical person’s body weight.
But, the fleshy covering of our body does more than its aesthetics purposes. Truth to be told, without it, our body will most likely evaporate.
Skin serves as an insulation guard that shields the body against harsh elements, extreme temperatures, and harmful sunlight. It also creates vitamin D, which is vital in converting calcium to stronger bones. Moreover, skin acts as a sensor, which has nerves that keeps us connected through the outside environment through our sense of touch. Lastly, it serves as a channel to excrete body waste in our body through the process of perspiration.
The skin is consists of three layers. The epidermis is the outermost one, which is made of cells regarded as keratinocytes. It is produced from the protein keratin, the material we can also see in our nails and hair.
These keratinocytes have several layers that steadily grows outwards. The exterior layers then die and flake off. On average, it takes around five weeks for the fresh coat of cells to reach the surface. The dead skin layer is called the horny layer, or the stratum corneum, which is ten times thicker on the soles of our feet. Langerhans cells can also be found in the epidermis, which keeps dangerous agents from entering the body, and alerts the immune system for any viruses or infection.
The epidermis is then connected to the second layer called the dermis. It is the layer responsible for providing strength and elasticity to the skin through its elastin and collagen fibers. To help regulate the temperature of the body, blood vessels limits the blood flow into the skin when it is cold, and increase it when it is hot to allow heat to escape from the body. It also homes a network of nerve receptors and fibers that detects feelings, such as pain, temperature, or touch, and then transmit the information to the brain.
Hair glands and follicles can also be found in the dermis. It contains ducts that go up through the skin. The body uses sweat glands to get rid of body waste fluids, such as lactate and urea, and decrease the internal temperature through the process of perspiration. The apocrine glands, which also homes in the dermis, develop starting the puberty stage. It provides scented sweat, which is connected to sexual attraction, though, it is also responsible for the presence of body odor, specifically in the armpits. Lastly, sebaceous glands release oily sebum that lubricates our skin and hair.
The skin’s third and innermost layer is called subcutis. It consists of a layer of fat that serves as an insulator and cushions the body from knocks and falls. Moreover, it also acts as a fuel reserve in case of a shortage of food.
Meanwhile, skin color is due to melanin, which is a pigment created in the epidermis. It helps protects the skin from the sun’s ultraviolet rays linked to causing skin cancer. Darker-skinned individuals tend to produce more and deeper pigments. They are mostly found in native to tropical areas, or those regions that are less-densely forested.
Additional reading:
- Human skin (Wikipedia)