Cerebellum Flashcards
- The axons of cerebellar granule cells are
a. parallel fibers.
b. mossy fibers.
c. climbing fibers.
d. the principal output from cerebellar cortex.
a) parallel fibers
Most of the output of the cerebellum is in the
form of
a. Purkinje cell axons.
b. climbing fibers.
c. axons of neurons in the deep cerebellar
nuclei.
d. mossy fibers
c) axons of neurons in the DEEP CEREBELLAR NUCLEI
The cortex of the cerebellar vermis projects mainly to the a. fastigial nucleus. b. dentate nucleus. c. interposed nucleus. d. vestibular nuclei.
A) fastigial nucleus
The flocculonodular lobe projects mainly to the a. fastigial nucleus. b. dentate nucleus. c. interposed nucleus. d. vestibular nucle
d) Vestibular nuclei
The primary fissure of the cerebellum marks the division between the a. anterior and posterior lobes. b. anterior and flocculonodular lobes. c. posterior and flocculonodular lobes. d. vermis and the medial hemisphere. e. medial hemisphere and the lateral hemisphere.
a) anterior & posterior lobes
Spinocerebellar fibers carrying information
about limb position project mainly to the:
a. medial hemisphere.
b. lateral hemisphere.
c. vermis.
a) medial hemisphere
Information traveling from the right cerebral
hemisphere to the cerebellum crosses the
midline
a. in the decussation of the superior cerebellar
peduncles.
b. on its way from the right thalamus (VL/VA) to
the pons.
c. in the pons, as pontocerebellar fibers.
d. This information does not cross the midline.
c) in the pons as pinto-cerebellar fibers
Where are the following found:
- Climbing fibers
- Output fibers from
the interposed
nucleus - Projections from the
cerebellum to
vestibular nuclei
- ICP
- SCP
- ICP
Where do mossy fibers originate from? Climbing fibers?
- Mossy = Ponto-Cerebellar (pontine Nuclei)
2. Inferior Olivary nucleus
What is the function of cerebellum?
MODULATE motor activity
- receives unconscious information
What is the major AFFERENT information to the cerebellum? (INPUT)
- Vestibular
- Proprioceptive & skin
- Receptor info
- Sensorimotor cortex
What is the 4 step pathway of information processing in the cerebellum?
- Mossy & Climbing fibers
- enter Cerebellar Cortex
- Purkinje cells activated
- DEEP NUCLEI
What is the major EFFERENT information from the cerebellum? (OUTPUT)
- Vesitbular Nuclei
- Thalamus
- Red Nucleus
(RT)
- no direct connection to spinal cord
TRUE OR FALSE: the Cerebellum directly projects on LMN?
FALSE
- project indirectly through LMN
What are the two groups of fibers that afferent information ENTERS the cerebellum?
- Mossy
2. Climbing fibers
What is the only AFFERENT projection in the Superior Cerebellar Peduncle?
VSCT
- Anterior Vestibulospinal Tract
Which peduncles contain afferent info? Efferent?
- ICP & MCP = AFFERENT
2. SCP = EFFERENT
How does the cerebellum send out information? To what locations?
Superior Cerebellar Peduncle!!!
through Thalamus & Red Nucleus
What is the floccularnodular lobe responsible for?
VESTIBULAR N.
nystagmus & unsteadiness
Which part of the Cerebellum is responsible for posture & axial muscles? Legs/arms?
MIDLINE
- LATERAL hemispheres
Which nuclei are contained in the:
- Vermis
- Medial Hemisphere
- Lateral Hemisphere
- vermis → fastigial
- medial hemisphere → interposed
(globose + emboliform) - lateral hemisphere →
dentate nucleus.
What fissure divides the Posterior lobe?
HORIZONTAL fissure
What does damage to the following result in:
Midline damage
Lateral damage
Damage to the flocculus
Midline damage causes postural instability.
Lateral damage causes limb ataxia.
Damage to the flocculus affects eye movements
Where does the ICP end? What does it originate from?
Flocculondular lobe
- Inferior Olivary Nucleus
Where does MCP originate from? End?
- Pontine
2. Hempispheres
Where does SCP originate from? End?
- DEEP Cerebellar Nuclei
2. Thalamus & Red Nucleus
What fibers project to the deep nuclei of the cerebellum?
PURKINJE fibers
- provide the tracts for SCP to exit cerebellum
What are the 3 inputs to the ICP? (afferents)
Efferents?
- Spinal cord
- Inferior Olivary Nuclei
- Vestibular & Cochlear N.
Output = Vestibular Nuclei.
(to cerebellar cortex)
What are the inputs to MCP?
Pontine fibers in the Cerebral cortex!!!
to cerebellar
In a cerebellar lesion, are signs ipsilateral or contralateral? What about Cerebral/Cortical lesion?
- IPSILATERAL
2. Cerebral = CONTRALATERAL
What are the efferents of SCP? Afferents?
- DEEP Cerebellar Nuclei
ends on:
- Red Nucleus
- thalamus - Afferent = VSCT
When does SCP decussate?
CAUDAL midbrain
What nucleus gives rise to fibers of MLF that originates from ICP?
Fastigial!
From Flocculonodular lobe
THE SCP & MCP project to which deep cerebellar nuclei?
- Interposed
2. DENTATE
What are the 3 layers of the cerebellum?
- Molecular
- Purkinje cell
- Granular
What are the only AXONS that leave the cerebellar cortex?
Purkinje cells
Which cells send their axons into the molecular layer as PARALLEL fibers?
Granule Cells
Where do mossy fibers synapse?
on GRANULE cells
- send an axon up which bifurcates
Where is PURKINJE cell output directed?
DEEP CEREBELLAR NUCLEI
- provide the output from the cerebellum
Which input is stronger, climbing or mossy?
CLIMBING
- so mossy causes many granule cells to fire together to turn on LOTS of parallel fibers
What is the path from inferior olivary nucleus to ICP?
- Inferior olivary nucleus
- Climbing fiber
- Purkinje cells
- Deep Cerebellar Nuclei
- INFERIOR CEREBELLAR PEduncle
What is the pathway of the mossy fibers?
- Mossy
- Granule
- Parallel
- PURKINJE
A positive Romberg sign (swaying with eyes closed) would be indiciative of a Cerebellar issue. True or False?
FALSE!!
- would affect sensory
= Tabes Dorsalis!!!
