The Skin

Although you may not have realised it, your skin is an organ too, and in fact it’s your largest organ.

Parts of the skin

Skin covers your body and has three layers:

  • the epidermis (outer layer), which provides a waterproof barrier and contains cells (melanocytes) that gives your skin colour
  • the dermis (middle layer), which contains tough connective tissue, hair follicles and sweat glands
  • the hypodermis or subcutis (deeper layer), which has fat and connective tissue

Functions of skin

Skin protects you from the weather. It also protects you against infections, and is part of the body’s immune system.

Skin helps control your body temperature. The blood flow to your skin increases to release heat from your body, and decreases to keep warmth in. This also affects how much moisture evaporates from your skin, which affects your body’s temperature.

Skin allows you to feel things – heat, cold, touch, pain and vibration.

Skin is water-resistant, stopping nutrients from leaching out of your body. Skin absorbs ultraviolet light from the sun, which is needed to make vitamin D.