inner ear - a complex system of cavities and canals in the temporal bone.These cavities and channels are interconnected and form a labyrinth.It is divided into the bone, and the membranous labyrinth, located inside it.The walls of the maze are divided perelimfoticheskim space.All these departments are filled with different body fluids: bony labyrinth and perilymphatic space - perilymph, membranous labyrinth - endolymph.

Both labyrinth divided into three parts: the vestibule (bony and membranous),
semicircular canals and cochlea.Snail is responsible for hearing, and the semicircular canals and the vestibule is the organ of balance - the vestibular apparatus.

semicircular canals of the inner ear are arranged in three directions perpendicular to each other.This arrangement corresponds to the three spatial dimensions - length, width and height.

In any position of the body in general and in particular of the head in space changes the effect of gravity on the inner ear.Because of this, the pressure fluid is displaced either to the lower or the side walls of the channels.When the rotational motion of the fluid in one channel is behind the move, the other moves by inertia.All these changes in pressure and fluid flow in channels before and excite the hair cells - receptors of the inner ear, they are transferred to the excitation of nerve fibers in the brain.

nerve center that receives signals from the vestibular system, located in the medulla oblongata.There's also the centers of regulating some physiological processes: breathing, digestion and circulation.Too much excitement center corresponding to the vestibular apparatus, capable of spread to these centers.Then the person is experiencing nausea, dizziness, sinking of the heart and other unpleasant feelings, which are collectively referred to as "rocking".This happens when the vestibular apparatus to work in unusual conditions for a man - in zero gravity or when a large drop height (for example, on an airplane), but a man leading a sedentary lifestyle, can lull even in the car.

similar mechanism of action and has a snail: her hair cells are also excited by moving the fluid filling the maze.The only difference is due to fluid motion: in the cochlea it is driven by vibrations of the eardrum, ear bones transmitted by the system.If disturbed mechanism of signal transmission from the hair cells in the nerve fibers, as is the case with sensorineural hearing loss suffer two feelings - hearing and sense of balance.