Chapter 15 Cerebellum Flashcards
Cerebellum function
adjusts posture and coordinates movement
cerebellar functions are nonconscious
does not directly influence muscle activity
optimizes cognitive, emotional, and social function
Mossy fibers
originate in the brainstem and spinal cord and convey somatosensory, arousal, balance, and cerebral cortex information into the cerebellum
Climbing fibers
originate in the inferior olivary nucleus and convey information regarding movement errors to the cerebellum
Cerebellum has 3 lobes
anterior
posterior
flocculonodular
Vestibulocerebellum
regulates equilibrium and is the functional name for the flocculonodular lobe
provides cerebellum with info about head movement and head position with respect to gravity
influence eye movement
damage causes unsteadiness when reaching for a book
Spinocerebellum
coordinates gross limb movements and is functional name for anterior lobe vermis and the paravermal regions
makes anticipatory, corrective, and responsive adjustments to movements
damage causes arm movements when reaching to be jerky and inaccurate
Cerebrocerebellum
coordinates precise, distal voluntary movements and functional name for posterior lobe and lateral part of anterior lobe
damage causes clumsy grasp of the book
Vestibulocerebellum receives input from
ipsilateral vestibular apparatus and ipsilateral vestibular nuclei in the brainstem
receives info from visual cortex
Spinocerebellum receives input from
the cortex
information from spinal cord to cerebellum travels in
spinocerebellar pathways and tracts
High-accuracy spinocerebellar pathways
posterior spinocerebellar pathway
cuneocerebellar pathway
posterior spinocerebellar pathway
transmits proprioceptive info from lower limbs and the lower trunk
cuneocerebellar pathway
Carries unconscious, proprioceptive information to the cerebellum from the upper extremities
2 internal feedback tracts
anterior spinocerebellar tract
rostrospinocerebellar tract
anterior spinocerebellar tract
rostrospinocerebellar tract
originate in spinal gray matter
inform cerebellum of UMN commands delivered to the interneurons that synapse with LMNs, activity of spinal reflexes circuits, and proprioceptive input to the spinal cord
anterior spinocerebellar tract
transmits info from thoracolumbar gray matter
rostrospinocerebellar tract
transmits info from the cervical spinal cord and T1to the ipsilateral cerebellum
Cerebro-cerebello-cerebral loop
connects cerebral cortex and lateral cerebellar cortex
cerbral cortex provides input to the pontine nuclei
denate nucleus is involved in motor planning
Goal directed functions of cerebellar posterior lobe
include focusing and shifting attention and selecting response
posterior lobe vermis is responsible for
processing, storage, and retrieval of emotional memories, regulating emotional responses, and optimizing social behavior
Red Nucleus
connects motor cortical areas with inferior olivary nucleus and cerebellum optimizing complex motor, cognitive, and emotional functions
signs of cerebellar motor dysfunction
abnormal motor execution that does not change with or without use of vision
ataxia
impaired coordination not caused by weakness, spasticity, or contracture
movement disorder common to all cerebellar lesions
vestibulocerebellum lesions
cause nystagmus, unsteadiness, and difficulty maintaining sitting and standing balance
anterior lobe vermis lesions
cause truncal ataxia, dysarthria,and gait and limb ataxia
Dysarthria
slurred, poorly articulated speech
Dysdiadochokinesia
inability to rapidly alternate movements
dysmetria
inability to accurately move an intended distance
cerebrocerebellar lesions
interfere with coordination of fine finger movements
Cerebellar cognitive affective syndrome
signs indicating cognitive and emotional deficits caused by cerebellar posterior lobe lesions
visuospatial, language, and goal-directed functions are impaired
Autism and ADHD both have
reduced cerebellar volume and decreased volume of the posterior vermis
Disorders that affect the cerebellum
MS, stroke, tumor, alcoholic degeneration, Arnold Chiari
Degenerative Disorders that affect cerebellum
spinocerebellar ataxia and multiple-system atrophy
