Cerebellum Flashcards
Paleocerebellum or Spinocerebellum: What are the parts? What does it control? What is its main input? What are the associated nuclei?
Vermis and adjacent cortices of anterior and posterior lobes (intermediate zone)
Adjusts ongoing movements and regulates muscle tone
Spinocerebellar tracts
Emboliform and globose nuclei (interposed nuclei)
Pontocerebellum or Neocerebellum: What are the parts? What does it control? What is its main input? What is the associated nucleus?
Most of cerebellar cortex (lateral zone)
Coordinates planning of movement
Sensory and motor cortices
Dentate nucleus
What are the layers of the cerebellar cortex? What cells (cell bodies) are found in each layer?
Molecular - stellate and basket cells
Purkinje - Purkinje cells
Granular - granule and Golgi
What is the function of granule cells of the cerebellum?
What fibers do they make up to some of these cells?
Excitatory to basket, stellate, Golgi and Purkinje cells
Parallel fibers
What is the function of basket cells in the cerebellum?
Inhibitory on the body of Purkinje cells
What is the function of stellate cells in the cerebellum?
Inhibitory on the dendrites of Purkinje cells
What is the function of Golgi cells in the cerebellum?
Inhibitory on mossy fibers in granular layer
What is the function of Purkinje cells in the cerebellum?
What neurotransmitter do they use?
Inhibitory on deep cerebellar nuclei (DEGF)
GABA
Mossy Fibers (of the Cerebellum): Where do their axons terminate? What kind of synapse do they form? What information do these fibers provide?
Dendrites of granular cells
Excitatory
Qualities of movements - muscles involved, direction, speed, tone
Climbing Fibers: Where do their axons originate? Where do their axons terminate? What kind of synapse do they form? What information do these fibers provide?
Inferior olivary nucleus
Dendrites of Purkinje cells
Excitatory
Errors in execution of movements
What are the pathways ascending to the cerebellum?
What kind of fibers are these pathways?
Anterior spinocerebellar
Posterior spinocerebellar
Cuneocerebellar
All mossy
Anterior Spinocerebellar Pathway:
What specific information does it provide?
Input from Golgi tendon organs, spinal interneurons, cutaneous receptors, fibers of descending tracts of distal part of lower extremities
Anterior Spinocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?
DRG
Follow fasciculus gracilis for short while
Anterior Spinocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?
Spinal border cells in lumber regions of anterior horn in lamina VII
Cross at AWC, ascend on anterior spinocerebellar tract, cross again in brainstem, enter cerebellum through SCP
Posterior Spinocerebellar Pathway:
What specific information does it provide?
Golgi tendon organs and muscle spindles from proximal part of lower extremities
Posterior Spinocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?
DRG
Follow fasciculus gracilis for short while
Posterior Spinocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?
Clarke’s column (nucleus)
Ascend on dorsal spinocerebellar tract, enter cerebellum through ICP
Cuneocerebellar Pathway:
What specific information does it provide?
Golgi tendon organs and muscles spindles from upper extremities
Cuneocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?
DRG
Ascend via fasciculus cuneatus
Cuneocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?
Lateral (external) cuneate nucleus
Ascend on cuneocerebellar tract, enter cerebellum through ICP
What is the general plan of cerebellar pathways?
Corollary motor discharge
Sensory feedback
Modulation of output
What are the motor monitoring pathways?
What is a general rule regarding these pathways?
Paleocerebellar
Pontocerebellar
Vestibulocerebellar
There is considerable overlap
Paleocerebellar Pathway:
What is the path of neurons for corollary motor discharge?
What is the path of neurons for sensory feedback?
What is the path of neurons for modulation of output?
CMD - red nucleus, inferior olivary nucleus, ICP
SF - muscle spindles and joint receptors, cerebellar tract, ICP
MO - Globose and emboliform nuclei, SCP, red nucleus, rubrospinal tract or other motor pathway, muscle
Pontocerebellar Pathway:
What is the path of neurons for corollary motor discharge?
What is the path of neurons for sensory feedback?
What is the path of neurons for modulation of output?
CMD - motor cortex, corticospinal tract, MCP
SF - sensory cortex, MCP
MO - dentate nucleus, SCP, VL of thalamus, motor cortex, corticospinal tract, muscle
Vestibulocerebellar Pathway:
What is the path of neurons for corollary motor discharge?
What is the path of neurons for sensory feedback?
What is the path of neurons for modulation of output?
CMD - vestibular nucleus, ICP
SF - semicircular canals, ICP
MO - fastigial nucleus, ICP, vestibular nucleus, motor pathway, muscle
Truncal Ataxia:
What is the cause?
How will a patient present?
What tests can be performed and what are positive results?
Lesion to vermis or flocculonodular lobe
Loss of equilibrium, wide stance, problems balancing, veering to one side, unsteady gait
Tandem gait test - patient falls or deviates to one side while walking a line
Romberg test - proprioception in dorsal columns, positive if swaying with eyes closed
Appendicular Ataxia: What is the cause? What is the effect? How will a patient present? What test can be performed and what are positive results?
Lesion to cerebellar hemispheres or lateral zone
Lateral motor systems, movement of extremities, skilled and fine voluntary or planned movements, errors in force, direction, amplitude and speed
Dysdiadochokinesia, pronation and supination problems, loss of muscle tone, dysmetria
Finger-nose-finger test - positive when wavering or missing target
