Touch is the oldest and the most primitive sense that we have. It is the first sense we experience in the womb and the last one we lose before death. The organ that is most associated with the sense of touch is the skin. The uppermost part of the skin is called epidermis, which is as thick as a piece of paper, and it protects the inner part. Below the epidermis, there is dermis. Dermis is where the sense of touch is originated from. It is filled with many tiny nerve endings, which gives the person information about the things with which the body comes in contact. The information is sent from dermis to the spinal cord, and from there it moves to the brain where the feeling is registered. We lose between 30,000 and 40,000 skin cells every minute, and this is because the skin renews itself to prevent itself from wearing away.
There are about 20 different types of nerve endings that sense different types of information. The 4 most common ones are heat, cold, pain and pressure. The most important receptor is probably the pain receptor because it is directly related to our safety.
Animals have their own unique way of getting the sense of touch, and the sensibility differs from one to another. As I talked about in the previous slide, humans use their skin to feel the sense of touch. The most sensitive areas in human body are around hairy areas, such as the hairline around the face and genitals, lips, nipples and fingertips. In case of cat and some other animals such as dogs, their whiskers operate as their main receptor of the sense of touch. Whiskers are located above the eyes, on the cheeks and muzzle, chin or lips. Cats use their whiskers to move in the dark; without whiskers, animals might bump into objects at night until new ones grow. Cats also use whiskers to check if the prey they hold in their mouths is alive or dead. Cats also have skin which is covered by millions of touch receptors that are hypersensitive to pressure, air currents and temperature....
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