The Skin (Part I)

February 22, 2010

The skin is the largest organ in the body that has many important functions which include the following:

  1. It protects the body from infection by preventing the invasion of harmful organisms.

  2. It protects the body from dehydration by preventing the loss of excessive fluids.

  3. It participates in the regulation of body temperature and protects the body from abrupt temperature changes.

  4. It protects the body against sun burns.

  5. It protects the internal tissues and organs.

  6. It helps excrete waste materials through perspiration.

  7. It generates vitamin D through the exposure to sun light and stores vitamin D.

  8. It has receptors through which we feel heat, cold, pain, pressure and touch.

The skin is made up of three layers: 1) Epidermis, 2) Dermis, 3) Hypodermis

The Epidermis:

It is the outermost layer of the skin which is the part of the skin that we can see, it is composed of five layers from inside to outside they are, Stratum basale, Stratum spinosum, Stratum granulosum, Stratum lucidum and Stratum corneum. The epidermis is continuously making new cells to replace the old ones, this process starts at the bottom of the epidermis moving toward the top of epidermis, the process takes between two to four weeks, as the newer cells continue to move up, older cells near the top die and rise to the surface of skin. 95% of the cells of the epidermis work to make new skin cells, the other 5% make a substance called melanin. Melanin is a pigment responsible for skin color, the darker the skin is the more melanin there is. Melanin protects us from getting burned by the sun's ultraviolet rays that is why when we go out into the sun these cells make extra melanin to protect us from getting burned and that's why our skin gets tan if we spend a lot of time in the sun. Melanin can't protect the body by itself therefore we wear sunscreens and protective clothing such as a hat to prevent painful sunburns, protecting the skin also can help prevent skin cancer.
