The Sense of Somesthesia
Touch is the action of the hand to perceive the external environment, the shape of objects, their texture, their temperature. But what about the rest of the body? It is very difficult to discriminate so well with a knee. This ability to perceive bodily sensations is called somesthesia. Touch is an aspect of somesthesia, such as skin sensitivity, visceral sensitivity, proprioception and nociception. Somesthesia represents all the nervous activity linked to the perception of the body.
Receptors of the Somesthesia
Receptors are small structures from which information is collected at the periphery (skin, muscles, joints and viscera). These structures ensure the transformation of physical, chemical and thermal energy into action potential: this is called transduction.
The pathways of somesthesia
Different stimuli will activate different receptors that are associated with different types of fibers. Each fibre will take a specific route to reach specific areas of the brain. Thus, the type of stimulation of the skin, muscle or tendon (or any other part of the body) will serve to target a specific region of the brain.