Our lips are pretty fantastic; they help us say words with ‘p’ in them, like ‘pretty’ or ‘pizza’ or ‘Peter Piper picked a peck of pickled peppers’. But, when you think about it, our lips are made up of skin cells… but they don’t look like the rest of our skin. In fact, our lips and our skin are different colours! Why is that? What are the differences between our lips and our skin that cause this colour difference?
Layers of Skin
Our lips and skin are composed of a three layer system. These layers, from exterior to interior, are:
- Subcutaneous Tissue
The layer that differs in size for different cells is the epidermis, which has 5 sub-layers, the top-most layer being the stratum corneum. This sub-layer is important for hydration of cells.
Differences between cells in lips and skin cells
In lip cells, the stratum corneum is thinner than in our other skin cells. Since this layer is thinner, the epidermis is thinner. This results in our blood vessels, which sit below the dermis (which sits under our epidermis!), being brought closer to the surface of our skin.
Our skin cells also contain a very dark pigment called melanin (which is important for UV protection!), which our lips don’t have much of. This lack of melanin coupled with the increased proximity of our blood vessels to the surface of our skin are the reasons why our lips are pink/red!
Next time: Chapped Lips
Whitmore, Elizabeth. 2009. How are lips different from other skin areas? HowStuffWorks.com. <http://health.howstuffworks.com/skin-care/lip-care/health/lips-different-skin.htm> February 06, 2013.