Massage action
Receptions of massage, acting on tissues, cause excitation of mechanoreceptors. Mechanoreception involves a number of qualities of arising sensations: pressure, touch, vibration and tickling, which are associated with the presence of skin receptors of four types.
Type I receptors are pressure receptors( force sensors), whose functions are to measure the strength of mechanical stimulation of the skin or the depth of its indentation. These receptors also show the duration of the pressure exerted.
Type II receptors are touch receptors( velocity sensors).Their function is to determine the rate of mechanical stimulation and its change, that is, the characteristics of mechanical stimulation in time.
Type III receptors are acceleration( vibration) receptors. Their function is to determine the acceleration of skin bias.
Type IV receptors are receptors that provide a tickling sensation. They react to the movement of the stimulus through the body, and in this case we are dealing with the psychophysiological manifestations of this type of reception, because, as a rule, one can not tickle a person himself.
In addition to these types of receptors, there are mechanosensitive free nerve endings in the skin. Some of them are temperature receptors, others serve as non-receptors( pain receptors).
Pacini's Tauri( Fatera-Pacini) are acceleration sensors, also called TP receptors. Taurus Maysnar - speed sensors, also called tactile Meissnerian bodies - are located only in areas of the skin that do not have hair( palm, sole, etc.).In hair-covered skin, the velocity sensors take the form of hair follicle receptors. Sensors of intensity in hairless skin are cellular complexes, or Merkel disks. In the deep layers of the skin( covered with hair and without hair), other intradermal receptors, the Ruffini calf, were found.
To all the above mechanoreceptors, afferent nerve fibers are suitable with a pulse rate of 30-70 m / s.
When exposed to the skin, which turns out to be any of the massage techniques, receptors of almost all types of the massaged area are excited, however, those that most closely match the type of massage are stimulated. For example, when vibrating massage techniques are used, vibration receptors( acceleration) are predominantly excited, while touching receptors touch( speed), etc. This fact explains the need to use all massage techniques, as well as the possibility of a multidirectional massage effect on the excitability of the nervous system independing on the strength, pace and duration of the application of various techniques.
Mechanical irritations, deforming the capsule of the receptors, cause the expansion of their envelope, as a result of which its permeability for sodium ions changes, which in turn leads to a decrease in the membrane resting potential and generation of the prescription potential, which is transferred to the afferent nerve fiber. As a result of the processes of temporal and sequential summation of receptor potentials on the nerve fiber, an action potential arises that enters the posterior roots of the corresponding segment of the spinal cord. Further, in the lemniscus and spinal-thalamic pathways, impulses enter the brain into the somatosensory cortex.