The skin

The skin is the largest organ in the body.

It covers the body, protecting it from injury, regulating its temperature and preventing it from becoming dehydrated.

Skin has two main layers of cells called the epidermis and the dermis.

Epidermis -- the top/outer layer of the skin

• It contains two main types of cells: squamous cells and melanocytes.

• The melanocytes produce melanin, the substance that gives skin its colour (pigment).

• When skin is exposed to sunlight, the melanocytes produce more melanin and the skin becomes tanned.

Dermis -- the layer underneath the epidermis

• Contains the roots of hairs; sweat glands; blood and lymph vessels; and nerves.