Vestibular apparatus

Vestibular Apparatus

The vestibular apparatus is a complex sensory system located within the inner ear that plays a crucial role in maintaining balance and spatial orientation. It is composed of two main components: the semicircular canals and the otolith organs.

Structure

The vestibular apparatus consists of five main parts: three semicircular canals and two otolith organs, the utricle and the saccule. These structures are filled with a fluid known as endolymph and contain specialized sensory cells called hair cells.

Semicircular Canals

The semicircular canals are three bony, fluid-filled tubes located in the inner ear. They are oriented at right angles to each other and are responsible for detecting rotational movements of the head.

Otolith Organs

The otolith organs, the utricle and saccule, are responsible for detecting linear movements and head position relative to gravity. They contain small crystals of calcium carbonate known as otoliths that move in response to changes in head position, stimulating the hair cells.

Function

The vestibular apparatus is primarily responsible for maintaining balance and spatial orientation. It does this by detecting changes in head position and movement, and sending this information to the brain. The brain then uses this information to coordinate movements and maintain balance.

Clinical Significance

Dysfunction of the vestibular apparatus can lead to a variety of symptoms, including dizziness, vertigo, balance disorders, and nystagmus. Conditions such as Meniere's disease, vestibular neuritis, and benign paroxysmal positional vertigo (BPPV) are all associated with vestibular dysfunction.

See Also

• Inner ear
• Balance disorder
• Vertigo
• Meniere's disease