Your skin is a huge sense organ with thousands of sensory receptors. Skin receptors are not only sensitive to touch and texture-telling you whether something is smooth or furry, for example. There are also receptors that respond to heat, and ones that respond to cold. Yet others tell you when something is putting pressure on you skin.
Some skin receptors are sensitive to all four. They are called free nerve-endings and they are thought to send out pain signals if messages from touch, heat, cold, or pressure receptors are too strong.
There are free nerve-endings wrapped around the hairs in your skin, sensitive to each hair’s slightest movement. Some areas of the skin are densely packed with nerve endings, as in the finger-tips, while others, as on the back, have comparatively few.
You have other senses besides the five main ones, including those of balance, hunger and thirst. Your sense of pain is very important – it warns you when your body is hurt or in danger.