Cerebellum and Brainstem Deep Structures Flashcards
What exactly does the Cerebellum do?
Modulates movement, aids in coordination and balance. Compensates for error by comparing intention with performance.
- Also contributes some to non-motor functions such as cognition, emotion and affective processing
- Appears to play a role in sequencing incoming sensory patterns and detecting temporal changes in the sequence of sensory events
Where are the Vermis and paravermian areas of the cerebellum located>
In the midline
What do the vermis and paravermian areas of the cerebellum control?
Axial musculature and trunk
What do the lateral hemispheres of the cerebellum control?
arms and legs
The floculonodular node is heavily involved in maintaining….
balance
Deep nuclei of the Cerebellum from lateral to medial
Dentate, Emboliform, GLobose, Fastigial
Don’t Eat Greasy Foods
What the hell are these nuclei?
Relay points for efferent fibers travelling from the cerebellar cortex to other brain regions
The dentate nuclei serve what hemispheres?
The lateral ones
The Emboliform nuclei serve what part of the cerebellum
Paravermal zone
The Globose nuclei serve what part of the cerebellum?
Paravermal zone
The Fastigial nuclei serve what part of the cerebellum?
The Vermis
Know Cerebellar Afferents and Efferents bundles
ok
3 layers of the cerebellar cortex (gray matter) are?
- Molecular layer
- Middle Layer
- Granular Layer
What neuron types are found in the molecular layer?
Basket and Stellate Cells
What Neuron types are found in the middle layer?
Purkinje cells
What Neuron types are found in the Granular layer
Golgi and Granule cells
Only output neurons of the cerebellar cortex are?
Purkinje cells
The only direct input to the purkinje fibers from outside the cerebellum is?
Climbing fibers from the olivary nuclei
What effect do the stellate and basket cells have on the purkinje fibers
inhibitory
Input from mossy fibers into the cerebellar cortex first passes through what?
Cerebellar glomerulus…These mossy fibers then synapse with the granule and golgi cell dendrites and then with Golgi axon terminals. The Granule cell then passes this modified information along to the purkinje cell
Three functional divisions of the Cerebellum
Vestibulocerebellum, Spinocerebellum, Cerebrocerebellum
Function of the Vestibulocerebellum
- made up by vestibular nuclei, flocconodular node, fastigial nuclei, inferior paravermis
coordinate eye, head, neck movements and maitain balance
Function of the spinocerebellum
- made up of vermis, superior paravermian layers, anterior lobe
coordinate trunk and proximal limb movement
Function of the Cerebrocerebellum
- made up of lateral parts of posterior lobe
coordinate fine motor planning of limbs and anticipate sensory consequences of movements
Right cerebellar hemisphere controls right arm, body and leg
Left controls left
Clinical signs of cerebellar dysfunction
unstable gait, tendency to fall (sailor’s gait)
- jerky, unsmooth movements accompanied by a tremor (uncoordinated movements)
- Ataxia (dis-coordination)
- Eye movement disorders
- Speech disorders
Superior Colliculus function
control of reflex movements that orient the eyes, head, neck in response to visual, auditory, and somatic stimuli
Periaqueductal gray matter
functions in the processing of autonomic and limbic activities
Aqueduct
connects 3rd and 4th ventricles
Edinger Westphal nucleus
parasympathetic innervation of the eye to constrict the iris and alter lens shape for accomodation
Cranial nerve III
Motor control of eyes
Spinothalamic tract
Fiber pathway to thalamus for pain/temperature from the periphery
Medial lemnisucs
Sensory pathway for proprioception connecting the nucleus gracilis and cuneatus with the thalamus
Medial geniculate
Thalamic relay nuclei for auditory information
Lateral Geniculate
Thalamic relay nuclei for visual information
Cerebral peduncle
fiber bundles of the corticospinal tract connecting the cerebral cortex to the brainstem
Optic tract
optic fibers from the optic chiasm to lateral geniculate
Substantia nigra
one of the nuclei involved in smooth motor control; degenerates in parkinsons
Red nucleus
Relay nuclei between cerebellum to the thalamus
Draw out brainstem structures from midbrain, pons, and upper medulla
ok
Know whether CN nuclei lie in the midbrain, pons, medulla, or transition points in between
ok, FA p434
A lesion at the base of the midbrain would cause what?
- Ipsilateral Occulomotor nerve paresis
- ## Contralateral hemiparesis (weakness on one side of body)
A lesion at the tegmentum (area of midbrain spanning from substantia nigra to cerebral aqueduct
- Ipsilateral occulomotor nerve paresis
- Contralateral tremor
- Contralateral ataxia
Midbrain base and tegmentum
Ipsilateral 3rd nerve paresis
Contralateral hemiparesis
Contralateral tremor
contralateral ataxia
Medial pons
contralateral hemiparesis
ipsilateral LMN
Facial paresis
Medial medulla
contralateral arm and leg weakness
contralateral decreasin in position/vibration
Ipsilateral tongue weak
Lateral medulla—fairly common
Ipsilateral ataxia, vertigo, nausea, ipsilateral decrease in face pain sensation, ipsilateral horner’s Dysphagia
