vestibular

Examples of vestibular in the following topics:

• Vestibulocochlear (VIII) Nerve

  • It consists of the cochlear nerve that carries information about hearing and the vestibular nerve that carries information about balance.
  • The vestibular nerve travels from the vestibular system of the inner ear.
  • The vestibular ganglion houses the cell bodies of the bipolar neurons and extends processes to five sensory organs.
  • The other two sensory organs supplied by the vestibular neurons are the maculae of the saccule and utricle.
  • Inner ear illustration showing semicircular canal, hair cells, ampulla, cupula, vestibular nerve, and fluid

• The Vestibular System

  • The vestibular system has some similarities with the auditory system.
  • Together, they make up what is known as the vestibular labyrinth .
  • It is the vestibular branch of the vestibulocochlear cranial nerve that deals with balance.
  • The structure of the vestibular labyrinth is made up of five vestibular receptor organs in the inner ear: the utricle, the saccule, and three semicircular canals.
  • Identify the structures of the vestibular system that respond to gravity

• Development of Hearing and Balance

  • Critical periods have been identified for the development of the hearing and vestibular system.
  • The vestibular wall will separate the cochlear duct from the perilymphatic scala vestibuli, a cavity inside the cochlea.
  • Critical periods have been identified for the development of hearing and the vestibular system.
  • Animals with abnormal vestibular development tend to have irregular motor skills.
  • Studies have consistently shown that animals with genetic vestibular deficiencies during this critical period have altered vestibular phenotypes, most likely as a result of lack insufficient input from the semicircular canals and dopaminergic abnormalities.

• Additional Sensory Systems

  • Two additional sensory systems are proprioception (which interprets body position) and the vestibular system (which interprets balance).
  • The vestibular system is the sensory system that contributes to balance and the sense of spatial orientation.
  • Some signals from the vestibular system are sent to the neural structures that control eye movements and provide us with clear vision, a process known as the vestibulo-ocular reflex.
  • While both the vestibular system and proprioception contribute to the "sense of balance," they have different functions.
  • The vestibular system, together with the cochlea, makes up the workings of the inner ear and provides us with our sense of balance.

• Ataxia

  • The term vestibular ataxia is employed to indicate ataxia due to dysfunction of the vestibular system, which in acute and unilateral cases is associated with prominent vertigo, nausea, and vomiting.
  • In slow-onset, chronic bilateral cases of vestibular dysfunction, these characteristic manifestations may be absent, and dysequilibrium may be the sole presentation.
  • Focal lesions - Any type of focal lesion of the central nervous system (such as stroke, brain tumur, multiple sclerosis) will cause the type of ataxia corresponding to the site of the lesion: cerebellar if in the cerebellum, sensory if in the dorsal spinal cord (and rarely in the thalamus or parietal lobe), vestibular if in the vestibular system (including the vestibular areas of the cerebral cortex).
  • Ethanol is capable of causing reversible cerebellar and vestibular ataxia.

• Balance and Determining Equilibrium

  • With hair cells in the inner ear that sense linear and rotational motion, the vestibular system determines equilibrium and balance states.
  • The neural signals generated in the vestibular ganglion are transmitted through the vestibulocochlear nerve to the brain stem and cerebellum.
  • Together, these components make up the vestibular system.
  • By comparing the relative movements of both the horizontal and vertical ampullae, the vestibular system can detect the direction of most head movements within three-dimensional (3-D) space.

• Introduction to Sensation

  • Two other senses, kinesthesia and the vestibular senses, have become widely recognized by scientists.
  • Vestibular senses detect gravity, linear acceleration (such as speeding up or slowing down on a straight road), and rotary acceleration (such as speeding up or slowing down around a curve).
  • Both kinesthesia and the vestibular senses help us to  balance.

• Sensory Modalities

  • The organ of equilibrioception is the vestibular labyrinthine system found in both of the inner ears.
  • The vestibular nerve conducts information from sensory receptors in three ampulla, each of which sense fluid motion in three semicircular canals caused by a three-dimensional rotation of the head.
  • The vestibular nerve also conducts information from the utricle and the saccule; these contain hair-like sensory receptors that bend under the weight of otoliths (small crystals of calcium carbonate) that provide the inertia needed to detect head rotation, linear acceleration and the direction of gravitational force.

• Female Reproductive Anatomy

  • Among the external structures are the vulva, which consists of the mons pubis, clitoris, labia majora, labia minora, and the vestibular glands.
  • The greater vestibular glands are found at the sides of the vaginal opening and provide lubrication during intercourse.

• Reception

  • Vestibular sensation, which is an organism's sense of spatial orientation and balance, proprioception (position of bones, joints, and muscles), and the sense of limb position that is used to track kinesthesia (limb movement) are part of somatosensation.