Cerebellum Flashcards
Purpose of the cerebellum
Coordinating contraction
E.g. contraction of agonists and relaxation of antagonists
Each cerebellar hemisphere controls the ____ half of the body
Ipsilateral
What does cerebellar dysfunction cause?
Ataxia (Jerky/uncoordinated movements)
Location of the cerebellum?
Posterior cranial fossa
How many hemispheres make up the cerebellum?
2 hemispheres
What connects the hemispheres?
Vermis
What are the lobes of the cerebellum?
Anterior
Posterior
Flocculo-Nodular
What are the fissures of the cerebellum?
Primary Fissure (superior surface)
Horizontal Fissure (superior surface)
Uvulo-Nodular Fissure (inferior surface)
Primary fissure location
Between anterior and posterior lobes
Horizontal fissure location
Between superior and inferior surfaces
Extends around lateral and posterior borders
Uvulo-nodular fissure location
Between posterior and flocculo-nodular lobes
Where can the anterior lobe be found?
Superior surface of the cerebellum
Where can the posterior lobe be found?
Between Primary Fissure and Uvulo-Nodular Fissure
Location of the Flocculo-Nodular Lobe
Anterior part of the inferior surface
What are the folia?
Folds of the cerebral cortex serparated by tiny transverse fissures
What are the functional divisions of the cerebellum?
Archicerebellum (Vestibulocerebellum)
Paleocerebellum (Spinocerebellum)
Neocerebellum (Cerebrocerebellum)
Archicerebellum
Components
Flocculonodular lobe
Ligula
Archicerebellum
Function
Position (balance)
Archicerebellum
Describe the pathway of the afferents to the archicerebellum
Receive afferents from vestibular nuclei
Transfered to inferior cerebellar peduncles
Received by the archicerebellum
Paleocerebellum
Components
Anterior lobe
Part of inferior vermis (uvula and pyramid)
Paleocerebellum
Function
Gross propulsive movements
Posture
Paleocerebellum
Describe the pathway of afferents to the paleocerebellum
Proprioceptive stimuli from anterior and posterior spinocerebellar tracts
Travel to inferior and superior cerebellar peduncles
Received by cerebellar cortex
Neocerebellum
Components
Posterior lobe (except uvula and pyramid)
Dentate nuclei
Neocerebellum
Function
Planning
Modulation
Voluntary Movements
Neocerebellum
Describe the pathway of fibers to the neocerebellum
Receives afferent fibers from cerebral cortex
Pontine nuclei fibers from pontine nuclei cross to opposite side
Pass through middle cerebellar peduncle to the cerebellum
Neocerebellum
Describe the pathway of fibers away from the neocerebellum
Project from dentate nucleus to the contralateral thalamus
Reach to motor cortex of frontal lobe
Gives rise to cortico-spinal pyramid tract
What substance forms the cerbellum?
Grey matter
What are the components of the grey matter?
Cerebellar cortex
Cerebellar nuclei
Cerebellar Cortex
3 layers of cerebellar cortex
External
Middle
Internal
Cerebellar Cortex
Neurons of the external layer
Stellate Cells
Basket Cells
Cerebellar Cortex
Neurons of the middle layer
Purkinge Cells
Cerebellar Cortex
Neurons of the internal layer
Granular Cells
Golgi Cells
Names of the Cerebellar Nuclei
Dentate
Emboliform
Globose
Fastigial
What structures connect the brainstem to the cerebellum?
Superior Cerebellar Peduncle (Midbrain)
Middle Cerebellar Peduncle (Pons)
Inferior Cerebellar Peduncle (Medulla)
Which blood vessel supplies the superior surface of the cerebellum?
Superior Cerebellar Artery (Basilar Artery)
Which blood vessel supplies the lateral part of the inferior surface of the cerebellum?
Anterior Inferior Cerebellar Artery (Basilar Artery)
Which blood vessel supplies the medial part of the inferior surface of the cerebellum?
Posterior Inferior Cerebellar Artery (Vertebral Artery)
What is ataxia?
Loss of control of voluntary movement
What are some features of ataxia?
Wide gait
Dysmetria
Dysdiadochokinesia
Intention Tremor
What are the causes of cerebellar ataxia?
Lesion in the one cerebellar hemisphere
Caused by tumor or vascular lesion
