Touch
- This article is about one of the five main senses. For other uses, see Touch (disambiguation)
Touch is one of the five main senses that animals have. It can be called the sense of body or the sense of touch. The system also has internal sensory receptors, and includes sensing temperature and pain. There is a special area in the brain used to processing input of touch. It is in the parietal lobe of the cerebral cortex.
An animal knows if something is against a part of its body. This is called the sense of touch. The process of touching something may be called feeling.[1]
Tiny touch sense organs under the skin help animals feel hardness, softness, and sharpness, for example. Animals also have sense organs which feel temperature and pain. Some parts of the body, such as fingertips have many more sense organs than others.
When animals touch things, nerve fibres attached to the sense organ sends messages to the brain through the central nervous system. The brain interprets the messages, and animals feel things.[2]
Touch as communication
Humans, and mammals in general, often touch each other. Touch is a kind of non-verbal communication. Behaviours based on touch are very important for keeping family and group members together ('bonding'). It is part of the 'glue' of their social life. Monkeys grooming each other's fur is a good example.
Touch Media
Touch is a crucial means of receiving information. This photo shows tactile markings identifying stairs for visually impaired people.
This diagram linearly (unless otherwise mentioned) tracks the projections of all known structures that allow for touch to their relevant endpoints in the human brain.
Gray's Anatomy, figure 759: the sensory tract, showing the pathway (blue) up the spinal cord, through the somatosensory thalamus, to S1 (Brodmann areas 3, 1, and 2), S2, and BA7
Gray's Anatomy, figure 717: detail showing path adjacent to the insular cortex (marked insula in this figure), adjacent to S1, S2, and BA7
Touch can result in many different physiological reactions. Here, a baby laughs at being tickled by an older sister.
The cortical homunculus, a map of somatosensory areas of the brain, was devised by Wilder Penfield.
Related pages
References
- ↑ Although 'feeling' has other meanings as well: I am feeling ill.
- ↑ Morris, Neil; Ting Morris (1998). Jim Miles, Lynne French (ed.). Children's First Encyclopedia. Branka Surla, Rosie Alexander. II Bardfield Centre, Great Bardfield, Essex CM7 4SL: Miles Kelly Publishing Ltd. ISBN 1-84084-332-2.
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