Sense of touch. Touch provides tactile, pressure, thermal and painful sensations , by stimulating specific nerve receptors, distributed throughout the skin surface.
Summary
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- 1 skin
- 2 Different sensations of the sense of touch.
- 3 Sensitivity of the sense of touch
- 4 Cutaneous receptors.
- 5 Sources
The skin
It is the largest organ in our body and the organ with the greatest 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 body has four million receptors to perceive pain, 500,000 to feel pressure, 150,000 to perceive cold , and 16,000 to perceive 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 pleasant 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. Sensations are perceived through receptors, which are responsible for sending the signal to the brain and are found throughout our body, distributed among the different layers of the skin .
skin receptors.
These are called corpuscles (Meissner, Ruffini, Paccini, and terminal bulbs of Krause, which have different functions:
- Meissner’s corpusclesallow us to identify the shape and size of objects, as well as differentiate smooth from rough.
- Pacinian 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, the weight is measured according to the effort that causes us to lift an object. That is why it is said that the weight is felt by the “muscular sense”.
- The Ruffini corpusclessense changes in temperature related to heat – our normal temperature is between 36 and 37 degrees. Especially sensitive to these variations is the surface or dorsal side of the hands.
- Krause’s corpusclesare responsible for registering 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 located behind the Rolando fissure.
