Vestibular System: What is it? Structure, Anatomy and Functions

It is an integral part of the labyrinth found in the otic capsule in the ear’s petrous portion of the temporal bone.

This system is the one that provides the balance of the body; therefore, if it is affected by any condition, it tends to affect the stability of the body, producing fainting or involuntary falls.

It consists of 5 different terminal organs, three semicircular channels sensitive to angular accelerations (head rotations), and two otoliths sensitive to accelerations.

The vestibular system is designed so that the body can do everything the brain commands by granting a sense of balance, from walking, running, and climbing steps to skateboarding, snowboarding, and surfing, among other activities that merit balance and precision.


This system is a collection of structures in the inner ear that also provides an awareness of spatial orientation, a sensation of whether the body is on its back or upside down.

The brain then integrates these data with other sensory information to coordinate smooth and timely body movements, thus achieving the desired activity without suffering a faint or an unsuspecting fall for no apparent reason.

The general lines of its operation are relatively complex actions and not something that is acquired innately at birth.


Because all living beings with legs and feet or legs learn to walk from minor, refine and refine these interactive systems. Every time you learn something new that requires balance (such as walking by bicycle or paddleboard), the brain modifies and refines these integration processes.


According to the ear’s structure, it is possible to discern which parts of the ear are composed, mainly auditory and part of the vestibular system.

The ear, also known as the pinna, meaning “wing” or “fin,” is the funnel-shaped external ear that directs sound into the ear canal, also known as the external acoustic meatus, ‘meatus’ is in Latin’ channel ‘or’ passage. ‘

This passage carries sound to the tympanic membrane, or eardrum, which reverberates to transmit sound to the bones of the inner ear.

Within the tympanic cavity, three auditory ossicles, or bones, collide against each other, transmitting sound waves that vibrate against the tympanic membrane to something called the oval window of the inner ear.

The oval window is the membranous connection point between the auditory ossicles and the fluid-filled structure of the inner ear, called the membranous labyrinth.

Half of the membranous labyrinth, the cochlea, is dedicated to converting sound waves into neuronal signals. In contrast, the vestibular system’s other half is dedicated to deriving its sense of balance.

Both halves use the vestibulocochlear nerve, which transmits neuronal signals to the brain for interpretation and integration.


In the vestibular half of the inner ear, there are three semicircular canals, which run in three different orientations because of their semicircular shape.

These orientations allow in the triangular vestibular system the orientation of the head and, consequently, the sense of balance based on the three reference points of the channels.

The vestibular system does so through three sensory structures, called ampullary crests, which join the ends of the semicircular canals.

It also has sensory structures that line the ends of the semicircular canals and transmit signals to the vestibulocochlear nerve concerning the rotation of the head.

Each is lined with a collection of tiny hair cells, named for the hair-like filaments called stereocilia, which project from the top.

The stereocilia are embedded in a considerable gelatinous substance called the dome, which, when pressed by the fluid on both sides, stimulates the stereocilia of the hair cells, which then conduct signals to the vestibulocochlear nerve.

In conclusion, the ear not only works to listen, but it also has the vestibular system that has the task of giving balance to the body, and if it is affected by an infection or an accident, dizziness or difficulties walking correctly because The brain would not be receiving the necessary information to understand the relationship of the external environment with the body.