Term
| Where is the vestibular system found? |
|
Definition
|
|
Term
| The vestibular organs (the part of the ear that senses motion) send their signals through the vestibular part of which cranial nerve? |
|
Definition
|
|
Term
| Which structures work on the right and left side to detect rotations of the head in all 3 directions (ANGULAR ACCELERATIONS)? |
|
Definition
|
|
Term
| How many semicircular canals are there? |
|
Definition
|
|
Term
| Which structures sense LINEAR ACCELERATIONS (such ads gravity)? |
|
Definition
|
|
Term
| What two structures make up the otolith? |
|
Definition
|
|
Term
| The (otoliths/semicircular canals) can tell you when your body is tilted one direction or another. |
|
Definition
|
|
Term
| moving your chin up and down (in a "yes" nodding motion) is called what? |
|
Definition
|
|
Term
| moving the ear towards the shoulder is called a what? |
|
Definition
|
|
Term
| the movement of shaking your head (as if saying "no") is called what? |
|
Definition
|
|
Term
| what is the reflex in which eye velocity compensates for head velocity? (Keeping visual field stable even when you are shaking your head very quickly) |
|
Definition
|
|
Term
| what is the reflex which allows head position to be maintained despite body movements? |
|
Definition
|
|
Term
| what is a reflex that involves postural changes in response to a vestibular signal? |
|
Definition
|
|
Term
| under normal circumstances, hair cells are somewhat (polarized/depolarized) and are firing a resting action potential rate |
|
Definition
|
|
Term
| Deflection of the stereocilia toward the kinocilium causes _____ channels in the apical portions of the stereocilia and kinocilium to open. |
|
Definition
|
|
Term
| K+ flows into the stereo/kinocilia from the endolymph, depolarizing the cell membrane. This depolarization in turn causes ________ channels at the base of the hair cells to open, allowing _______ to enter the cell |
|
Definition
voltage-gated Calcium channels
Calcium |
|
|
Term
| ____ influx into the stereo/kinocilia causes synaptic vesicles to release neurotransmitter into synaptic clefts |
|
Definition
|
|
Term
| which neurotransmitter is most commonly released from hair cell cilia? |
|
Definition
|
|
Term
| increased release in glutamate causes depolarization of the membrane in the post-synaptic cell, which increases the firing rate of the vestibular (efferent/afferent) fibers |
|
Definition
|
|
Term
| sterocilia moving towards kinocilia (increases/decreases) the firing rate of the afferent fibers |
|
Definition
|
|
Term
| stereocilia moving away from the kinocilia causes (increase/reduction) of calcium influx, a net (increase/reduction) in neurotransmitter release, (hypo polarization/hyperpolarization) of the post-synaptic membrane, and (increase/decrease) in the firing rate of vestibular afferent fibers |
|
Definition
| stereocilia moving away from the kinocilia causes REDUCTION of calcium influx, a net REDUCTION in neurotransmitter release, HYPERPOLARIZATION of the post-synaptic membrane, and a REDUCTION in the firing rate of vestibular afferent fibers |
|
|
Term
| the anterior portion of the sacculus has cells that are sensitive to movement in which directions? |
|
Definition
|
|
Term
| which directions of movement does the utricle sense? |
|
Definition
| medial and lateral, posterior and anterior |
|
|
Term
| which directions of movement does the sacculus sense? |
|
Definition
| up and down MOSTLY, (also forwards and backwards?) |
|
|
Term
| moving your head to the right, the utricle of one ear will move/sense _____ and the utricle of the other ear will move/sense ______ |
|
Definition
| one will move/sense medial, one will move/sense lateral |
|
|
Term
| what are the "little rocks" in the ear that increase the effective force on the stereocilia (they sit in a gelatinous matrix where stereocilia insert) |
|
Definition
|
|
Term
| the swelling at the base of each semicircular canal is called what? |
|
Definition
|
|
Term
| the structure in the ampulla that is analogous to a sail that acts to intercept fluid motion is called what? |
|
Definition
|
|
Term
| what type of acceleration is the cupula sensitive to? |
|
Definition
|
|
Term
| an angular acceleration causes fluid in the semicircular canals to move in the (same/opposite) direction, which displaces the cupula |
|
Definition
|
|
Term
| what are the 3 different semicircular canals? |
|
Definition
horizontal canal
anterior canal
posterior canal |
|
|
Term
| if you move your head horizontally to the right while the head is tilted down 30 degrees, which canals will increase firing rate and which canals will decrease firing rate? |
|
Definition
| moving horizontally to the right, the right horizontal canal will increase firing rate, and the left horizontal canal will decrease firing rate |
|
|
Term
| the right anterior canal is paired with which canal on the left side? |
|
Definition
the left posterior canal
(RALP and LARP) - R anterior/L posterior, L anterior/R posterior |
|
|
Term
| What head motion excites only the horizontal canals? |
|
Definition
| tilting the head down 30 degrees and rotating the head |
|
|
Term
| Where do the two descending vestibular spinal tracts descend from? |
|
Definition
one descends from the LATERAL VESTIBULAR NUCLEUS
one descends from the MEDIAL VESTIBULAR NUCLEUS |
|
|
Term
| the (lateral vestibular nucleus/medial vestibular nucleus) is more involved in postural musculature |
|
Definition
| lateral vestibular nucleus |
|
|
Term
| which tract (lateral vestibulospinal tract/medial vestibulospinal tract) is more appropriate for innervation of the trunk muscles? |
|
Definition
| medial vestibulopinal tract |
|
|
Term
| which tract is involved in not letting you fall over when you have your eyes closed? |
|
Definition
| lateral vestibulospinal tract |
|
|
Term
| which tract has a huge influence on anti-gravity muscles? |
|
Definition
| lateral vestibulospinal tract |
|
|
Term
| The lateral vestibulospinal tract runs into the (dorsal/ventral/lateral) horn which is appropriate for innervating which muscles? |
|
Definition
ventral horn
distal leg muscles |
|
|
Term
| In addition to the descending vestibular tracts there are also projections from the vestibular nuclei to the thalamus, from which information is relayed to which two places int the cortex? |
|
Definition
| parietal and somatosensory areas of the cortex |
|
|
Term
| vestibular signals sent to the cortex via the thalamus can allow you to do what? |
|
Definition
| move around with your eyes closed or in a dark room |
|
|
Term
| CN 6 (abducens) innervates which muscle in the vestibulo-ocular reflex? |
|
Definition
|
|
Term
| About 40% of the cells in the abducens nucleus are internuclear neurons that project to the (ipsilateral/contralateral) oculomotor nucleus |
|
Definition
|
|
Term
| Turning your head with your finger held in front of you, the finger seems to stay still due to which reflex? |
|
Definition
|
|
Term
| In the vestibule-ocular reflex, turning your head to the left will cause afferents on the (right/left) to increase firing and turn eyes to the right |
|
Definition
|
|
Term
T or F
Vestibular responses are good at signaling slow changes |
|
Definition
False
Analogy is with slow movement of a glass of water, the water does not move much |
|
|
Term
| what movements does the utricle sense? |
|
Definition
| movements in the the horizontal plane (forwards, backwards, left, right) |
|
|
