vestibular system

A Dictionary of Psychology

vestibular system n. An organ in the membranous labyrinth of the inner ear mediating sensations of balance, orientation, and movement, containing the otolith (or statolith) organs that are responsive to linear acceleration (including gravity) and the semicircular canals that are responsive to angular acceleration. When the head is accelerated rapidly in a straight line, a gelatinous membrane covered with heavy otoconia crystals of calcium carbonate tends to remain stationary through inertia, bending or displacing hair cells that project into the fluid at different angles from the maculae of the utricle and saccule, causing the hair cells to trigger nerve impulses that are sent to the brainstem and cerebellum, leading to reflex movements of muscles of the eyes, neck, limbs, and trunk, and exciting neurons in the central nervous system that mediate the perception of motion and orientation in space. The otolith organs also respond to gravity, which according to the general theory of relativity is equivalent to accelerating an object upwards at 9.8 metres per second squared. The three semicircular canals detect angular acceleration by means of hair cells that project into the gelatinous membrane of the cupula where a fluid (endolymph) acts as an inertial mass resisting angular acceleration, displacing the hair cells in the direction opposite to the direction of movement and causing adjoining neurons to send nerve impulses to the brainstem and cerebellum. Also called the vestibular apparatus. See also Aubert effect, kinaesthesis, mechanoreceptor, proprioception, vestibular nerve, vestibular nystagmus, vestibular sense, vestibulo-ocular reflex.[From Latin vestibulum a forecourt or entrance]

Find more facts and information related to the .
© A Dictionary of Psychology 2001, originally published by Oxford University Press 2001.

Related newspaper, magazine, and trade journal articles from HighBeam Research

(Including press releases, facts, information, and biographies)

	The singing ear ; ...which is thought to work by movements of hair cells in the inner ear, ramps up the volume...amplification process goes awry: The hair cells in the ear, which transduce sound to...34). Mammalian ears have two types of hair cells, outer and inner. Scientists agree that... Read more
	Deaf defying; geneticists and physiologists are disentangling the causes to deafness and beginning to glimpse ways of doing something about it.(Science and Technology) ; HAIR cells are tiny-about fifteen-thousandths of...the number or the effectiveness of the hair cells rather than, say, damaging the auditory nerve that runs from the ear to the brain. Hair cells can also be damaged by environmental... Read more
	Outer hair cells: The inside story ; The neurobiology of hair cells is reviewed, including their transduction apparatus, the...potentials, and the similarities and differences between inner hair cells and outer hair cells (OHCs). Intracellular recordings from hair cells in vivo... Read more
	With gene therapy, ears grow new sensory cells. (Getting an earful). ; ...within the inner ear, and these so-called hair cells respond by sending electrical impulses...Conventional wisdom holds that once damaged, hair cells in people and other mammals don't regenerate...ears of adult guinea pigs to sprout new hair cells. It's the first time anyone has ... Read more
	New hope for people with hearing loss. (studies indicate mammals can repair inner-ear damage) ; ...held that people who've lost specialized hair cells in the inner ear cannot make up for their...with inner-ear damage can regenerate hair cells. But many researchers believed this process...researchers have shown regeneration of hair cells in adult mammals, Rubel says. Forge... Read more
	Good vibrations. (hair cells hold the secret of hearing)(includes related articles on the pinna and insects that can hear bat ultrasound) (Cover Story) ; ...sacrificing. Those hearing receptors are called hair cells, specialized sensory cells that are among...princesses turning straw into gold, the inner hair cells transform the mechanical forces of sound...ocean to the shore to dry land. Yet the hair cells at its core have hardly been ... Read more
	UW RESEARCHER MAKES HEARING LOSS BREAKTHROUGH.(NEWS) ; ...new cells, which scientists call hair cells, inside their ears, but that the cells worked. Other teams have grown hair cells before, Gubbels said. What's truly...about our work is that the extra hair cells were shown to be functional and... Read more
	Breakthrough possible in hearing restoration ; ...restoration -- Scientists regenerate inner-ear hair cells By MALCOLM RITTER, THE ASSOCIATED PRESS...grow new sound-sensing cells, called hair cells, in the spiral-shaped chamber called...percent - are due to lost or damaged hair cells. The cells can be damaged by aging, infection... Read more
	New cell culturing method pumps up the volume.(Research Roundup) ; ...certain inner-ear disorders. Damage to hair cells is a key factor in hearing and balance...amphibians can quickly regrow damaged hair cells, humans cannot. Until now, scientists...inducing avian cells to differentiate into hair cells via a process known as mesenchymal-to-epitheli... Read more
	Hair cell regeneration: An exciting phenomenon . . . But will restoring hearing and balance be possible? ; Abstract- Sensory hair cells of the inner ear are susceptible to...balance problems. The discovery that hair cells can regenerate in birds and other...words: audiology, auditory, genomics, hair cells, hearing, regeneration, stem cells... Read more

For more facts and information, see all related premium articles

Related entries from encyclopedias, dictionaries, and thesauruses

	vestibular system vestibular system Human beings, in common with other...are collectively referred to as the vestibular system. They form a very small part of the...of the elements of this system. The vestibular system is deeply embedded in the temporal... Read more
	vestibular sense vestibular sense n. The sense of balance and orientation, governed by the vestibular system . See also Aubert effect , vestibulocochlear nerve . Read more
	vestibular nystagmus vestibular nystagmus n. Any form of nystagmus controlled by the vestibular system and activated by head movements. See also post-rotational nystagmus , vestibulo-ocular reflex . Read more
	vestibular nerve vestibular nerve n. One of the two major branches of the vestibulocochlear nerve , transmitting information related to balance from the vestibular system .[From Latin vestibulum a forecourt] Read more
	The Reproductive System ...different in structure and function. The male reproductive system The primary organs in the male reproductive system are the testes. Their main function is to produce male...sex organs) are the scrotum and penis. The Reproductive System: Words to Know Acrosome (AK-ro-sohm): Tip of the ... Read more

See all related entries