Subcutaneous Tissue

Illustrated cross section of skin.
The hypodermis is composed of subcutaneous tissue, an all-important insulator that regulates your body's temperature.
© Steidl

The layered look is definitely "in" when it comes to your skin. Like a tank top, followed by a blouse and topped off with a sweater to create a complete ensemble, your skin has three layers that each serves an important purpose. Though you cannot see it, the innermost layer -- the tank top, if you will -- is composed of subcutaneous tissue, an all-important insulator that regulates your body's temperature and protects your insides.

It's difficult to appreciate the subcutaneous tissue, also called the hypodermis, without considering the skin's other two layers, the epidermis and dermis. The epidermis is the outer layer that encases your entire body [source: American Medical Association]. Though it might look thin and flimsy, the epidermis is tough as nails when it comes to protecting you from bacteria and environmental toxins. It also holds a whole lot of water and is responsible for that healthy glow -- or lack thereof [source: WebMD]. In addition, this very useful layer gives skin its color.


Under the epidermis lies the dermis. Among other things, the dermis is responsible for your skin's strength and elasticity, thanks to the collagen and elastin fibers it contains [source: WebMD]. Nerves in the dermis allow you to feel the gentlest touch and the deepest pain. You'll also find glands and hair follicles in the dermis.

And now to the subcutaneous tissue -- it is an important (although often unappreciated) line of defense in your body. Subcutaneous tissue is composed of an insulating layer of fat and blood vessels [source: WebMD]. Though many people aren't particularly grateful for the fat in their bodies, the fat in the subcutaneous layer would likely be missed if it were to disappear, considering that it protects the organs and bones and keeps the body's temperature where it ought to be.

There's much to love about the subcutaneous tissue. Keep reading to find out everything this "tank top layer" does for you.


Function of the Subcutaneous Tissue

Medieval knights often wore armor to protect themselves from arrows and swords. Just like that armor, your subcutaneous tissue, though not nearly as clunky, works around the clock to protect not only your bones, but also your inner organs and delicate tissues that make up the soft parts of your body.

If sports are more your thing, think about subcutaneous tissue in terms of the pads a football player dons before a big game. Sandwiched between the outer layers of skin and the underlying muscle and bones, it is there to offer your insides additional protection against potential injuries [source: P&G]. Since it is mostly made of fat, it is spongy and resilient. You'll no doubt appreciate this extra cushion next to your bones the next time you take a tumble.


Besides providing protection, the hypodermis also sees to it that your internal temperature is not overly hot or overly cold. The subcutaneous tissue works with the blood vessels that run through it to keep your temperature normal and consistent [source: WebMD]. The sweat glands that exist at this level of skin help keep you cool in the summer. This internal cooling system can help your body deal with anything from a hot afternoon in the sun to a fever caused by sickness.

Unfortunately, as you get older, your subcutaneous tissue begins to thin out. As a result, the loss of extra insulation can put you at risk to extreme temperatures and injury from falls [source: MedlinePlus]. Hypothermia becomes more of a threat because aging skin is not as efficient as younger skin in maintaining body temperature. You sweat less due to loss of subcutaneous tissue -- and this makes it harder to keep cool [source: MedlinePlus]. Also, since certain medications are absorbed through subcutaneous tissue, this can affect how your body reacts to those medicines.

To learn more about subcutaneous tissue and how it benefits your body, visit the links on the next page.


Lots More Information

Related HowStuffWorks Articles

  • American Medical Association. "Skin." (Accessed 9/25/09)
  • MedlinePlus. "Aging changes in skin." U.S. National Library of Medicine and the National Institutes of Health. 8/10/2008. (Accessed 9/25/09)
  • MedlinePlus. "Skin Conditions." U.S. National Library of Medicine and the National Institutes of Health. (Accessed 9/25/2009)
  • P&G. "The Subcutaneous Fat Layer." The World of Skin Care. (Accessed 10/7/09)
  • WebMD. "Skin Problems and Treatments Center." (Accessed 9/25/09)
  • WebMD. "Skin Conditions: Understanding Your Skin." (Accessed 9/25/09)