Cerebellum Flashcards
What side of the cerebellum can the vermis be seen?
Dorsal view
What side of the cerebellum can the tonsil be seen
Ventral
In what view can the tonsil, flocculus, nodule, sup/mid/inf cerebellar peduncles be seen?
View from the pons through the 4th Ventricle
What makes up the Archicerebellum / Vestibulocerebellum?
Flocculonodular lobe and part of vermis
What does the flocculonodular lobe and part of the vermis make up?
Archicerebellum / Vestibulocerebellum
What makes up the Paleocerebellum / Spinocerebellum?
- most of vermis
- adjecent region of cerebellar hemispheres
What makes up the neocerebellum / Cerebrocerebellum?
lateral parts of cerebellar hemispheres
What is made up of most of the vermis as adjacent region of cerebellar hemispheres?
Paleocerebellum / spinocerebellum
What is made up of the lateral parts of the cerebellar hemispheres?
Neocerebellum / Cerebrocerebellum
What is the function of the vestibulocerebellum?
- Coordinates muscles involved in maintaining BALANCE and constancy of VISUAL FIELDS.
- recieves input from Vestibular apparatus of inner ear
What is the function of the spinocerebellum?
Co-ordinates muscles involved in POSTURE and LOCOMOTION
What is the function of the cerebrocerebellum?
coordinates movements of distal limbs, particularly FINE skilled movements of hands.
What side of the body does the cerebellum infulence>?
SAME side (IPSILATERAL)
What does proprioception and sensory info from the spinal cord pass through in order to enter the cerebellum?
Inferior cerebellar peduncle
Describe how the cerebellum helps to co-ordinate movement?
1) Cerebellum recieves proprioceptive and sensory information via the ipsilateral spinocerebellar tract which enters the cerebellum via the inferior cerebellar peduncle.
2) Recieves planned movement info from the contralaterl cortex via the pontine and inferior olivary nucleus. Info from the pontine nucleus crosses the midline and enters the cerebellum via the middle cerebellar peduncle.Info form the inferior olivary nucleus crosses the midline and enters via the inferior cerebellar peduncle.
3) The planned movement info and the proprioceptive info are processed by the cerebellum.
4) The new co-ordinated movement is sent to the contralateral cortex.
5) The cortex then sends a signal down the brain stem, where it decussates and goes on to control muscles on the same side as the cerebellum.
What cerebellar functional division also has a role in motor learning?
Cerebrocerebellum
What is Ataxia?
Ataxia is lack of co-ordination
What is truncal ataxia?
Inability to sit or stand without falling over.
Caused by a midline lesion affecting the vestibulocerebellum.
Most commonly caused by medulloblastoma
What is Gait ataxia?
The lower limbs are unco-ordinated this produces a wide based gait with staggering.
Caused by lesion of spino-cerebellum.
Most common in alcoholics due to degeneration of cerebellar neurons in paravermal areas,
What results from a lesion of the cerebellar hemisphere?
Incoordination of voluntary movement.
Patients show:
- tremor of intent
- past pointing or dysmetria (overshooting)
- Adiadochokinesia (inability to co-ordinate hands)
- Dysarthria (unclear articulation of speech)
- Nystagmus
What lesion causes inco-ordination of voluntary movement with the following symptoms:
1) Tremor of intent
2) Past pointing or dysmetria (overshooting)
3) Adiadochokinesia (inability to co-ordinate hands)
4) Dysarthria (unclear articulation of speech)
5) Nystagmus
Lesion of cerebellar hemisphere
What is type of ataxia is most common in alcoholics?
Gait ataxia - affects the lower limbs, producing staggering and wide based gait.
Caused by lesion of spinocerebellum
What type of ataxia is seen in a lesion of the spinocerebellum?
Gait ataxia
Wide based gait with staggering
What lesion causes gait ataxia?
Lesion of spinocerebellum
What type of ataxia is most commonly caused by medulloblastoma?
Truncal ataxia
inability to sit or stand without falling
What type of ataxia is caused by a lesion of the vestibulocerebellum?
Truncal ataxia
Inability to sit or stand without falling
What lesion causes truncal ataxia?
Lesion of vestibulocerebellum
