What are touch and pain?
There are many nerve endings in the skin, which are sensitive to touch, pressure, pain, cold and heat. The brain receives the messages sent by the sense organs. The information received by the brain is analyzed to know what is happening at any point on the skin.
Receptors in our Skin
The different receptors in the skin are shown in the figure. The pressure receptors 1. Are buried deep in the skin. Touch receptors 2. Are near the surface of the skin. Cold 3. And heat 4. Receptors are also near the surface of the skin. Pain receptors 5. are simply free nerve endings. Some areas of the skin have more sense organs than others. The fingertips, the tip of the nose, and the lips have large number of touch receptors.
When you touch an object, more than one type of a receptor is stimulated. When you hole a glass of water, the receptors of touch, pressure and cold are stimulated, but holding a glass of water does not stimulate pain receptors. These require higher pressures or temperatures before they are stimulated in to sending signals to the brain.