Cerebellum Flashcards
brain structure that is responsible for the integration of sensory perception and motor output
cerebellum
situated on the ponto-medullary junction, this part of the cerebellum receives vestibular signals; lesions here cause deficits in visual tracking and oculmotor control
flocculonodular lobe
name the 3 functional divisions of the cerebellum, and what each is responsible for
vermis: tone, posture and executive function of trunk
paravermis: tone, postue and exec function of limbs
lateral hemispheres: (mostly) timing of body movements, balance, and also higher functions like memory and language
input from this brainstem nucleus projects to the cerebellum via these special climbing fibers, whose main function is to generate error signals
inferior olivary nucleus
these nuclei in the basis pontis convey the motor plan to the cerebellum from the cortex
deep pontine nuclei
all spinocerebellar fibers enter the cerebellum as what type of fibers?
mossy fibers
the inferior olivary complex receives signals from what two sources of input?
contralateral spino-olivary tract (projecting from VSCT)
ipsilateral red nucleus
heavily myelinated band surrounding the inferior olive that is formed by the rubro-olivary fibers in the central tegmental tract
olivary amiculum
what are the two ways that vestibular inputs get into the cerebellum?
- relay from the vestibular nuclei through the ICP ipsilaterally
- directly into the ICP (monosynaptic pathway)
the cerebellum receives these ipsilateral inputs regarding muscle tone, via the inferior peduncle
reticuar formation inputs
receives all corticopontine fibers (14 million!) and sends mossy fiber projections relaying motor plan into the contralateral MCP
deep pontine nuclei
all precerebellar mossy fibers terminate on cells in which layer of the cerebellum?
granule cell layer
type of cerebellar cell that receives climbing fiber inputs from the inferior olivary complex
purkinje cell
True or false: deep cerebellar nuclei receive only mossy fiber input.
False. They receive both mossy and climbing fiber input
True or false: purkinje cells receive both mossy and climbing fiber input
True. They receive climbing fibers directly and mossy fibers indirectly (via branching granule cells)
This structure is the major output for the cerebellum
deep cerebellar nuclei
these cells provide inhibitory feedback to granule cells
golgi cells
most numerous neuron in the brain, with t-shaped axons known as parallel fibers that go into the superficial molecular layer of the cerebellum to form synapses with purkinje cells
granule cells
True or false: parallel fibers of granule cells make stronger synapses with Purkinje cell dendrite than do climbing fibers
False. Parallel fibers make relatively weaker excitatory (glutamatergic) synapses with spines in the Purkinje cell dendrite, whereas climbing fibers provide very powerful excitatory input to the proximal dendrites and cell soma.
True or false: some Purkinje cells directly target vestibular nuclei via ICP
True. Purkinje cells also target the deep cerebellar nuclei to regulate its firing.
the mnemonic “don’t eat greasy food” corresponds to what?
the 4 deep cerebellar nuclei from lateral to medial: Dentate nucleus Emboliform nucleus Globose nucleus Fastigial nucleus
what is the most common clinical presentation of a cerebellar deficit?
course tremors upon movement
blood supply to the cerebellum comes from what arteries?
PICA, AICA, and the superior cerebellar artery
True or false: all cerebellar syndromes cause ipsilateral signs.
True
Lesions to the cerebellar midline cause what kind of primary deficit?
truncal ataxia (drunken sailor gait)
Paravermal lesions in the cerebellum cause what kind of primary deficit?
limb ataxia
_____ lesions of the cerebellum cause deficits in speech, learning, and detecting errors in performance.
Hemisphere
