DK Science: Touch
Your sense of touch works by means of special sensory receptors scattered all over your body?s surface. These receptors allow you to feel an amazing range of sensations, from the pain of touching a searing hot iron to the tickling of a feather as it brushes against your skin. The receptors send messages along nerves to the spinal cord and brain, where the information is processed.
Touch receptors are types of specialized nerve ending. Meissner?s corpuscles detect fine touch and are found in hairless parts of the body, such as the lips, palms, and fingertips. Other types of receptor are sensitive to pressure, stretching of the skin, vibration, or hair movements.
Some areas of the skin, such as the fingertips and palms, are folded into ridges. These help improve both touch sensitivity (as they hold more receptors) and grip. The pattern of ridges and grooves provides a means of identification, because everyone has their own unique ridge pattern.
Developed in the 19th century by a Frenchman, Louis Braille, the Braille system allows blind people to read. Words are represented by a series of raised dots, which the reader recognizes by running his or her fingers over the page. The ability to read Braille relies on the extreme sensitivity of the fingertips to touch.