Sense of touch. Touch provides tactile, pressure, thermal and painful sensations , through stimulation of specific nerve receptors, distributed throughout the skin surface.
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- 1 The skin
- 2 Different sensations of the sense of touch.
- 3 Sensitivity of the sense of touch
- 4 The skin receptors.
- 5 Sources
It is the largest organ in our body and the organ with the highest tactile sensitivity. The sense of touch is not only found in the hands, it is present in all the skin that covers our body.
This sense is so extensive and complex that the organism has four million receptors to perceive pain, 500,000 to feel pressure, 150,000 for perception of cold and 16,000 for heat .
Different sensations of the sense of touch.
The sense of touch allows us to appreciate the external sensations of cold, heat, pressure , texture, vibration , tickling, as well as the weight we hold, the force that our muscles exert, etc. From intrauterine life the fetus is able to respond to tactile stimuli such as thumb sucking.
The sense of touch is extremely important for every human being . The sense of touch allows us to enjoy a caress, the warm rays of the sun, the cool wind, and endless pleasurable sensations. And it protects us against sensations that can cause us harm or pain, called nociceptors.
Sensitivity of the sense of touch
It is so sensitive that, even with our eyes closed, we can identify objects, textures, temperatures, etc. The sensations are perceived by means of receptors, which are in charge of sending the signal to the brain and are found throughout our entire body, distributed among the different layers of the skin .
These are called corpuscles (Meissner, Ruffini, Paccini, and Krause terminal bulbs, which have different functions:
- Meissner’s corpusclesallow us to identify the shape and size of objects, as well as to differentiate between smooth and rough.
- The Pacini corpusclesare what determine the degree of pressure we feel; They allow us to realize the consistency and weight of objects and to know if they are hard or soft. In some cases, weight is measured according to the effort caused by lifting an object. That is why it is said that weight is felt by the “muscular sense”.
- Ruffini’s corpusclesperceive temperature changes related to heat – our normal temperature ranges from 36 to 37 degrees. Especially sensitive to these variations is the surface or back of the hands.
- Krause corpusclesare responsible for recording the sensation of cold, which occurs when we come into contact with a body or a space that is at a lower temperature than our body .
The different impressions of touch are transmitted by the different receptors to the cerebral cortex, specifically to the area behind Rolando’s fissure.