The vestibular system is a group of structures in the inner ear that helps the body maintain balance, sense head movement, and understand its position and movement in space.
It consists mainly of three semicircular canals and two structures called the utricle and saccule. The semicircular canals detect rotational movements of the head, such as turning or nodding. The utricle and saccule detect linear acceleration and the effects of gravity, helping the brain determine the position of the head.
Specialized sensory cells within these structures detect movement and changes in orientation. They send signals through the vestibular nerve to the brain, which combines this information with input from the eyes, muscles, and joints to help maintain balance and coordinate movement.
The vestibular system also helps stabilise vision during head movement, allowing a person to keep their gaze relatively steady while walking or turning.
QUICK FACT
- The vestibular system contributes to balance but does not work alone; vision and sensory information from the muscles and joints also play important roles.
- Problems affecting the vestibular system may cause dizziness, vertigo, imbalance, or difficulty keeping the eyes steady during head movement.
- The vestibular system is located in the inner ear, alongside the cochlea, which is responsible for hearing.
COMMONLY CONFUSED WITH
- Cochlea: The spiral-shaped structure of the inner ear responsible for converting sound vibrations into electrical signals for hearing.
- Auditory nerve: Carries hearing-related signals from the cochlea toward the brain. Vestibular signals travel through the vestibular nerve, which joins the auditory nerve to form the vestibulocochlear nerve.
- Vertigo: A sensation that a person or their surroundings are moving or spinning. It is a symptom, not the name of the vestibular system itself.
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