Vestibular system
The vestibular system is the sensory Système principal of the perception of the movement and the orientation compared to the vertical. It is thus at the base of the direction of the balance. The sensory receivers of the vestibular system are located in the Oreille intern. The disorders of the vestibular system can lead to Vertige S.
The vestibular system consists of a peripheral sensor composed of the posterior labyrinth (semicircular channels, utricule, and saccule), Nerf vestibulocochléaire and of its cores encephalic.
Semicircular channels and perception of rotations
The three semicircular channels are laid out according to the three plans of space, they are presented in the form of Tore S (circular hollow tubes) containing a liquid, the endolymphe. At the time of a rotation movement, the Force of Coriolis involves a displacement of the liquid compared to the channels which is detected by the lashes of the vestibular cillées cells located on the wall of the channels. The orthogonal provision of the three channels thus makes it possible to detect a movement whatever the axis of the rotation. Vestibular information is transmitted to the Cerveau via the vestibular nerve , then the Nerf vestibulocochléaire and a relay in the vestibular cores .
Macular system and perception of linear accelerations
The perception of linear accelerations rests on the other cavities of the vestibular system which are the utricule and the saccule, which form the macular system. The macular adjective (of the Latin mackled, spot) refers to the receiving sensory located on the utricule and the saccule, the acoustic spots (in spite of their name they do not play any functional part in the Audition). With the difference of the other cillées cells, the macular mechanoreceptors are " lestés" by Otolithe S, small concretions limestones limed with the lashes by a viscous gel. During a linear acceleration their movement of Inertie is converted into nervous message. The Pesanteur terrestrial (vertical and downwards directed) is a particular acceleration which is detected by the macular system what informs the organization about its orientation in space.
Related articles
- vestibular Giddiness
- Syndrome
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