Cerebellum Flashcards
What layer of grey matter contains the cell bodies of basket cells and stellate cells?
Molecular layer
What is the deepest layer of grey matter? What cells does it contain?
Granular layer
Contains granule cells and a few Golgi cells
What are the efferent fibers from the cerebellar cortex?
Purkinje fibers
Most gray matter neurons tend to be ____ and use the NT ____, except for granule cells.
Inhibitory
GABA
What nuclei are inhibited by Purkinje cells?
Cerebellar and vestibular nuclei
Which neurons are the smallest? What NT does it use?
Granule cells
Glutamate
What grey matter cells synapse with Purkinje cells? What is their action?
Stellate cells and basket cells
Inhibitory
What are the afferent neurons in the gray matter? What is their general action?
Climbing fibers and mossy fibers
Excitatory
Where do the gray matter afferents send collateral branches?
Deep cerebellar nuclei
Where do the climbing fibers arise from?
Inferior olive
What cells do the climbing fibers synapse with?
Purkinje cells
What afferent fiberrs convey information about movement errors to the cerebellum?
Climbing fibers
What afferent fibers synapse with granulocytes?
Mossy fibers
What information do the mossy fibers convey?
Somatosensory, arousal, equilibrium, cerebral cortex motor info to cerebellum
What is the function of the vestibulocerebellum?
Influence eye movement and postural ms. of head and body
What is the anatomic name of the vestibulocerebellum?
Flocculonodular lobe
What information is transmitted to the flocculonodoluar lobe? Where does it send information to?
Receives info from vestibular receptors and visual areas
Sends ouput to vestibular nuclei
What is the functional name for the vermis and paravermal region of the cerebellum?
Spinocerebellum
What part of the spinocerebellum is associated with the medial upper motor neurons?
Vermis
What part of the spinocerebellum is associated with the lateral upper motor neurons?
Paravermal region
What is the function of the vermis and paravermal region?
Control ongoing movement via brainstem descending tracts
Monitors gait and station
What information is conveyed by the spinocerebellum?
Somatosensory info, internal feedback from spinal interneurons and sensorimotor cortex
What is the functional name of the lateral hemispheres of the cerebellum?
Pontocerebellum/Cerebrocerebellum
What is the function of the cerebrocerebellum?
Coordination of planned, timed, voluntary movements
Fine movements for fractionation
What part of the cerebellum do the cerebral cortex and pontine nuclei send their information?
Pontocerebellum/Cerebrocerebellum
The dorsal Nucleus of Clark is found at what spinal levels?
C8-L2
What do the restiform and juxtarestiform bodies comprise?
Inferior cerebellar peduncle
Which cerebellar tracts carries unconscious proprioception from the lower limb?
Anterior and posterior spinocerebellar tracts
Where does the first order neuron of the posterior spinocerebellar tract enter, ascend through, and then synapse?
DRG => Gracile fasciculus => Nucleus dorsalis of Clark (C8-L2)
What do the axons of the cuneocerebellar tract carry?
Unconscious proprioception from the upper limb
Where do the first order neurons of the cuneocerebellar tract enter, ascend, and then synapse?
Enter via DRG => Ascend in cuneate fasciculus => Synapse in accessory/external/lateral cuneate nucleus (lower medulla)
What is the path of the anterior spinocerebellar tract?
- Lamina of dorsal horn
- Crosses Anterior White Commissure to contralateral side
- Ascends through Anterior spinocerebellar tract
- Enters cerebellum through superior cerebellar peduncle
- Crosses back to ipsilateral side
Where do the posterior spinocerebellar and cuneocerebellar tracts enter the cerebellum?
Inferior cerebellar peduncle
Afferents from what enter the cerebellar cortex via the middle cerebellar peduncle?
Pontine Nuclei
Afferents from what structures enter the cerebellar cortex via the inferior cerebellar peduncle?
Inferior olive
Spinal cord
Vestibular nuclei
The efferents of the deep cerebellar nuclei mainly pass through what structure?
Superior cerebellar peduncle
What are the interposed nuclei?
Globose and Emboliform nuclei
Where would the lesion be if the patient was unable to tandem walk?
Vestibulocerebellum
(Also probably spinocerebellum)
Patient is seen sitting in his bed, appears to be shaking and is unable to sit still. Upon examination, he has nystagmus and is unable to walk with one foot in front of the other. Where is his lesion?
Vestibulocerebellum
Disease in what structures can cause midline ataxia?
Vestibulocerebellum
Spinocerebellum
Patient is asked to walk around the room and appears to have a wide stance and staggering gait. Normal eye exam and has normal speech. Where is his lesion?
Spinocerebellum
What is dysdiadochokinesia?
Inability to rapidly alternate movements
What is dysmetria?
Inability to accurately move an intended distance
What is an action tremor?
Intention tremor: shaking of the limb during voluntary movement, especially at the end of the movement
Upon a patient examination, he tells you the history with slow, poorly articulated speech. He is unable to rapidly flip his hands back and forth, and appears shaky when touching his nose and then your finger. What disorder is this? Where is the lesion located?
Appendicular ataxia
Cerebrocerebellum
A positive Romberg test with eyes open and closed is indicative of what disorder?
Cerebellar ataxia
What is the difference between cerebellar and sensory ataxia?
Cerebellar - normal vibration, proprioception, and ankle reflexes, + romberg with both eyes open and closed
Sensory - abnormal vibration, proprioception, ankle reflexes, +romberg only with eyes closed
How do you test vestibulocerebellum and spinocerebellum?
Station
Walking
Tandem gait
How do you test cerebrocerebellum?
Rapid alternating movements
Finger-to-nose
Toe-to-finger
Heel-to-shin
Rebound and check reflex
Speech
