The skin is the largest organ in the human body, both by surface area and weight — an adults skin is approximately 16% of the total body weight. Serving as a protective barrier between the body’s internal environment and the external ambient environment, it helps regulate our temperature and protects us from injury and many other environmental influences. But its ability to provide its own protection against the harmful effects of the sun’s UV radiation is limited.
The skin consists of two main layers, the outer and the inner layer. The layer covering all is known as the ‘horny’ layer. The outer layer of this is the epidermis. It contains, among other things, cells including the melanocyte cell that produces melanin. Melanin gives our skin the colour we call a suntan. The inner layer beneath the epidermis is the dermis, containing hair roots, sweat glands, blood, lymph vessels and nerves.
The human body is made up of millions of cells, which work together to perform different functions. They constantly reproduce themselves exactly, except when they have been damaged or are abnormal. This is the case with cancerous cells.