The fenestra cochleae is in the __________ and is aka the _________.
cochlea; round window
The fenestra vestibuli is in the ___________ and is aka the _________.
vestibule; oval window
What are the 2 components of hair cells?
kinocilum (one long cilium), sterocilia (bunch of small cilia)
For rotary movement and dynamic equilibrium, the receptor units are ____________; they are embedded in the _________ in each ___________ of semicircular ducts.
cristae ampullares; cupula; ampulla
For linear acceleration and static equilibrium, the receptor cells are __________, which are embedded in the __________ in each ____________.
maculae; otolithic membrane; utricle and saccule
What does it mean that vestibular fibers are bipolar sensory neurons?
there is a dendritic portion receiving the stimulus and an axon portion carrying the stimulus out
Primary vestibular fibers are axons coming from the __________ and going to... (2)
vestibular ganglion; vestibular nuclei in the brainstem and fastigial nucleus in the cerebellum
What 3 structures meet at the cerebellomedullary angle?
CN VIII, cerebellum (ventral aspect), and rostral extent of the medulla
How is a signal transmitted through the vestibular system?
head moves--> endolymph hits the cupula--> as cupula moves, it causes vibration in the kinocilum--> discharge of transmitter substances--> picked up by vestibular n. dendrites--> signal to vestibular ganglion--> primary vestibular fibers leave vestibular ganglion and transmit signal to vestibular nuclei in brainstem or fastigial nucleus in cerebellum
What are the 4 pairs of vestibular nuclei in the brainstem?
rostral, caudal, lateral, medial
The rostral vestibular nuclei are responsible for _____________; they send fibers to the ____________.
conjugate eye movement; extraocular nuclei of CN III, IV, VI
The caudal vestibular nuclei sends fibers to the ____________.
The lateral vestibular nuclei send out fibers that form the ________________ to regulate __(2)__; it sends fibers to ___________.
lateral vestibulospinal tract; muscle tone and balance; all the muscles of the body
The medial vestibular nuclei send out fibers that form the _______________ to regulate _________ in the __(2)__.
medial vestibulospinal tract; muscle tone; cervical and thoracic limb muscles
Axons from the vestibular nuclei of the brainstem to their targets of distribution.
secondary vestibular fibers
Within the spinal cord, the lateral vestibulospinal tract increases _________ and decreases _________.
ipsilateral extensor tone; contralateral extensor tone
Within the spinal cord, the medial vestibulospinal tract helps to coordinate _______________ and _____________.
activity of the limb and trunk; movement of the head
Within the brainstem, the extraocular nuclei associated with the vestibular system regulate _________.
conjugate eye movement
Within the brainstem, the vomition center of the vestibular system is the site of __________, which can contribute to ___________.
collateral fiber synapse; motion sickness
The vestibulocerebellar tract send primary fibers to the ____________ and secondary fibers to the ___________ of the cerebellum to control __________.
fastigial nucleus; flocculonodular lobe; balance
The special tract formed by secondary vestibular fibers from all of the vestibular nuclei.
medial longitudinal fasciculus
What are the 2 branches of the medial longitudinal fasciculus, and where do they go?
ascending branch to form the vestibulomesencephalic tract to extraocular LMN nuclei; descending branch to contribute to medial vestibulospinal tract to regulate extensor tone
The _____________ is formed by the ascending branch of the medial longitudinal fasciculus and goes to the __________.