Vestibular System Flashcards
Where are the auditory and vestibular receptors located?
Auditory and vestibular receptors are located in the inner ear, deep inside the temporal bone.
The ________ houses the auditory and vestibular sense organs.
bony labyrinth
The bony labyrinth consists of a series of cavities in what bone?
temporal bone
The membranous labyrinth consists of fine membranes (epithelia) that create a series of ?
interconnected sacs and ducts
The membranous labyrinth is filled with a specialized fluid called _____________
endolymph
________ lies outside the membranous labyrinth in the space between the bony and membranous labyrinths
perilymph
In each labyrinth (left and right) the auditory apparatus consists of the ______
cochlea
The vestibular apparatus consists of what two sets of sensory structures?
Three semicircular canals or ducts
and a pair of otolith organs, called the utricle and the saccule
What does the vestibular system detect?
The vestibular system detects position and motion of the head in space by integrating information from peripheral receptors located in the inner ear
The vestibular system provides the nervous system with information that is important in what two areas?
- reflex control of eye movements (the vestibulo-ocular reflex, VOR)
- reflex control of upright posture (the vestibulospinal reflex (VSR)
The semicircular canals or ducts are oriented so they can detect ____?
angular acceleration in three planes (horizontal, anterior, and posterior) and direction of head movement.
Both ends of each semicircular canal terminate in the ________
utricle
Each semicircular canal has an enlargement called the ______, where it joins the utricle.
ampulla
In one region of the ampulla, the epithelium of the canal is thickened and contains specialized receptor cells called the?
vestibular hair cells
A gelatinous mass called the _______ surrounds the hair cells
cupula
Sensory transduction is based on _______
inertia
Hair cells are stimulated only during changes in?
the rate of motion ( e.g., during acceleration of the head).
Vestibular hair cells consist of a single tall ____ and 40-70 shorter _______
kinocilium and 40-70 shorter stereocilia
Bending of the hairs towards the kinocilium causes _________
depolarization (leading to an increase in the firing rate of CN VIII)
Deflection of the hairs in the opposite direction (away from the kinocilium) causes?
hyperpolarization (and a decreasing firing rate in CN VIII).
Hair cells are arranged in each horizontal canal so that the axis of polarity (depolarization vs. hyperpolarization) points which way?
toward the center of the head
The horizontal canals lie in approximately the same plane on each side and they work together to detect?
motion.
The otolith organs provide the nervous system with what two types of information?
linear acceleration and head position with respect to gravitational forces
Hair cells are located within the utricle and saccule, supported by the _______ in each chamber
macula