Skin Facts
The basics...
The skin is one of the largest organs in the body. On average, it has a surface area of about 1.8 m2 and makes up about 16% of our bodyweight.
The skin has three layers: the epidermis, the dermis and the subcutis (see figure).
- The epidermis is the outer layer. It is made up of cells called keratinocytes; these produce keratin, which provides the skin with its structure. The epidermis also contains pigment cells, which give the skin its colour.
- The dermis is the middle layer. It consists mainly of collagen, providing strength and toughness. It also contains elastin, which provides the skin’s elasticity.
- The subcutis (or subcutaneous layer) contains sweat glands, blood vessels and fat. It also has some collagen fibres for support.
References
Dermatology. An Illustrated Colour Text. Gawkrodger DJ, Ardern-Jones MR (eds). Churchill Livingstone Elsevier 2012 (5th edition).
Ageing changes in skin – Overview. Available at http://www.umm.edu/ency/article/004014.htm
What is the function of the skin?
The skin has many important functions. These include:
- Protection: The skin acts as a barrier, protecting us from physical damage, trauma and infection.
- Temperature control: Our skin helps to maintain our core body temperature by absorbing or losing heat. The amount of heat absorbed or lost depends on the blood flow to the skin and how much we sweat.
- Sensation: Along with our ears, eyes, nose and tongue, the skin is one of our sensory organs, allowing us to feel (and react to) pain, touch etc.
Reference
Dermatology Nursing. A Practical Guide. Hughes E, Van Onselen J (eds). Churchill Livingstone 2001.
What happens to our skin as we get older?
- With ageing, the outer layer of the skin gets thinner.
- The number of pigment-containing cells decreases, but those that remain increase in size. Ageing skin therefore appears paler and more translucent, but may have large pigmented spots called liver spots.
- The skin loses its strength and elasticity, particularly in areas that are exposed to the sun.
- All of these changes mean that we have an increased risk of skin injury as we get older. In fact, more than 90% of older people have some type of skin disorder.
Reference
Ageing changes in skin – Overview. Available at http://www.umm.edu/ency/article/004014.htm
[accessed 1 Nov 2012].
What can I do to help protect my skin?
- Most skin changes are related to exposure to the sun, so you should use a good quality sunscreen when outdoors (even in the winter) and wear protective clothing and hats.
- Good nutrition and drinking plenty of water are also helpful. Dehydration increases the risk of skin injury.
- Keep your skin moist with lotions and other moisturisers and try to avoid soaps that are heavily perfumed.
Reference
Ageing changes in skin – Overview. Available at http://www.umm.edu/ency/article/004014.htm
[accessed 1 Nov 2012].