Question

1. Any object moving through space (such as an animal’s head)has six degrees of freedom. Three of these aretranslational. This means that motion canoccur along the x-, y-, or z-axis. Simply put, this means movingforwards or backwards, moving sideways, ore moving up and down. Theremaining three degrees of freedom arerotational, i.e. roll, pitch, and yaw.The primary sensory input for motion of the head is enabled bythe

left and right retina in combination with cranial nerve pairII

left and right vestibular apparatus in combination with cranialnerve pair VIII

2. Translational motion is detected by the neuroepithelia ofthe

otolith organs

ampullae within the semicircular canals

3. Rotational motion is detected by the neuroepithelia ofthe

otolith organs

ampullae within the semicircular canals

4. Recall that the vestibulo-ocular reflex enables the eyes toremain fixed on target and that extrinsic eye muscles areinnervated by brainstem α-motor neurons. What role does the mediallongitudinal fasciculus play in the vestibulo-ocular reflex?

central integration

links the vestibular nuclei with brainstem motor nuclei

5. Descending projections from the vestibular nuclei enablepostural adjustments of the head and body. Any stereotypical changein head position that promotes balance ismediated by the vestibulo-cervical reflex. This name stems from thefact that most of the α-motor neurons that control the position ofthe head are located in the motor nuclei of the

brainstem

cervical cord

6. Any stereotypical change in bodyposition that promotes balance is mediated by thevestibulo-spinal reflex. Does this reflex implement the γ-loop?

yes

no