Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/96

Click to flip

96 Cards in this Set

  • Front
  • Back
Where is the Cerebellum located?
In the posterior cranial fossa
4 Subdivisions of the crebellum:
1. Flocconodular lobe
2. Vermis
3. Anterior lobe
4. Posterior lobe
What separates the anterior lobe from posterior?
Primary fissure
A lesion of the cerebellum results in:
Uncoordinated movements
What is the blood supply to cerebellum? (3)
-Superior cerebellar artery
-AICA
-PICA
Which arteries are more common to see infarcts in?
-SCA
-AICA
What makes up each subdivision of the cerebellum?
Folia
Folia are:
little leaves of neural tissue
Where are the Cerebellar tonsils?
On the undersurface of the cerebellum.
What can happen to the cerebellar tonsils?
They can herniate thru foramen magnum if there is increased intracranial pressure
What is the Flocconodular lobe composed of?
-2 flocculi
-1 nodule
What separates the flocconodular lobe from the posterior lobe?
The posterolateral fissure
What structure is the flocconodular lobe a part of? What does it control? (3 things)
-Part of the vestibulocerebellum
-Controls equilibrium, eye movement, and balance.
What is the longitudinal cerebellar subdivision in the midline?
Vermis
What is the vermis part of and what does it control?
-Part of the spinocerebellum
-Controls axial and proximal limb movement
What is the area just lateral to the vermis called?
The Intermediate Zone
What is the Intermediate Zone part of and what does it control?
-Part of spinocerebellum
-Controls distal limb movement
Where is the Lateral zone?
Just lateral to the intermediate zone.
What does the Lateral zone control?
Planning and initiating of movement
What is the Lateral zone part of?
The cerebrocerebellum
What are the 5 major cell types that send efferents from the cerebellum?
1. Purkinje
2. Golgi
3. Stellate
4. Basket
5. Granule
Which efferent cells send out excitatory efferent fibers?
ONLY GRANULE
What cells give the most output?
Purkinje
What do the inhibitory fibers use as a NT?
GABA
What do the granule cells use as a NT?
Glutamate
What makes purkinje cells special?
They are the largest cell in the brain.
What do granule cells send output to?
All other cell types
What do Golgi cells send their inhibitory output to?
Granule cells
What do Basket cells inhibit?
Purkinje cells
What do Stellate cells inhibit?
Purkinje cells
How do purkinje cell axons run relative to cerebellum folia?
Perpendicular
How do Granule cell axons run relative to cerebellum folia?
Parallel
What are the 2 afferent fiber types that carry info to the cerebellum?
1. Climbing fibers
2. Mossy fibers
What is the nature of the afferent fibers from the cerebellum?
Both are excitatory
How do climbing fibers work, what do they excite?
Excite up to 10 purkinje cells, but each purkinje cell is only touched by one climbing fiber.
What do Mossy fibers excite?
Granule cells
Where does purkinje output go?
To the deep cerebellar nuclei
What are the 3 layers that make up the cerebellar internal structure? In what order?
1. Molecular
2. Purkinje cell layer
3. Granular layer
(outer -> inner)
What lies internally to the granular layer?
White matter
5 Things in the Molecular layer:
1. Dendrites of purkinje cells
2. Parallel fibers of granule cells
3. Climbing fibers of inferior olivary nucleus
4. Stellate cells
5. Basket cells
What is in the Purkinje cell layer?
Purkinje cell bodies
What is in the Granular layer?
-Granule cells
-Golgi cells
-Mossy fiber dendrites
What are the functions of the Deep Cerebellar Nuclei?
-To receive climbing/mossy fiber input on its way in.
-To receive cerebellar input on its way out.
What are the deep cerebellar nuclei?
The major output neurons of the cerebellum.
What are the 4 deep cerebellar nuclei, going from medial->lat?
Fat Girls Eat Dinner
-Fastigial
-Globose
-Emboliform
-Dentate
What is the synaptic circuit of the cerebellum that starts with climbing fibers?
1. Climbing fibers excite
2. Purkinje cells which inhibit
3. Deep cerebellar nuclei
What is the synaptic circuit of the cerebellum that starts with Mossy fibers?
1. Mossy fibers excite
2. Granule cells which excite
3. Purkinje cells which inhibit
4. Deep cerebellar nuclei
What is the nature of Climbing fiber firing?
Complex; 1-2 spikes per second
What is the nature of Mossy fiber firing?
Simple; Steady, 50-100 spikes/second
What inhibitor interactions occur in the cerebellum?
-Basket/stellate cells in granular layer inhibit purkinje
-Golgi cells in molecular layer inhibit granule cells
What is the function of the complex climbing fiber spikes?
To modulate the Purkinje cell response to mossy input.
What are the 4 major afferents to the cerebellum?
-Vestibular labyrinth
-Cortex
-Spinal cord
-Monoaminergic nuclei
How does information get from the vestibular labyrinth to the cerebellum?
1. Directly
2. Indirectly via Vestibular nuclei
What does info from the vestibular labyrinth ultimately reach? What type of info is it?
The vestibulocerebellum; this is info about balance.
How many major afferents are there to the cerebellum? What are they?
5
-Vestibular labyrinth
-Superior cerebellar peduncle
-Middle cerebellar peduncle
-Inferior cerebellar peduncle
-Monoaminergic fibers from the brain stem
Why is the inferior cerebellar peduncle (ICP) particularly important?
Because all circuits pass through it.
Where is the Spinocerebellum?
in the vermis and intermediate zone
How do afferents get into the Spinocerebellum?
Via the inferior cerebellar peduncle
(restiform body)
What 3 tracts pass thru the inferior cerebellar peduncle on their way to the spinocerebellum?
1. Olivocerebellar tract
2. Dorsal spinocerebellar tract
3. Cuneocerebellar tract
What does the olivocerebellar tract come from?
The CONTRALATERAL inferior olivary nucleus (ION)
What does the Dorsal Spinocerebellar tract come from?
What type of information does it carry?
The ipsilateral spinal cord and lower medulla
-Gives info about the axial and proximal limb.
What does the Cuneocerebellar tract come from?
The ipsilateral spinal cord and lower medulla
Does the Olivocerebellar tract only project into the spinocerebellum?
No; it also goes to the cerebellar hemisphere via the inferior cerebellar peduncle.
What is the Ventral Spinocerebellar Tract pathway?
Start: contralateral spinal cord
Ascends: Ventral spinocerebellar tract
Passes thru: Superior cerebellar peduncle
Terminates: contralateral spinocerebellum
Where in the cerebellum does the ventral spinocerebellar tract terminate?
In the anterior lobe.
What is important to remember about the Ventral spinocerebellar tract?
It crosses twice
What will lesions in the cerebellum result in?
Ipsilateral symptoms
Where does the Corticopontocerebellar Tract originate?
In the Cortex
Where does the corticopontine tract project to from the cortex?
To pontine nuclei
How are the fibers of the corticopontocerebellar tract carried from the pontine nuclei to the cerebellum?
Via the middle cerebellar peduncle
What part of the cerebellum does the corticopontocerebellar trat ultimately reach?
The contralateral Cerebrocerebellum
What 2 monoaminergic fibers are afferents to the cerebellum?
1. Serotoninergic fibers from the Raphe nuclei
2. Noradrenergic fibers from the Locus ceruleus
What are the major efferents from the cerebellum?
1. Flocconodular lobe to vestibular nuclei
2. Cerebellar cortex to deep cerebellar nuclei
What is the function of Vestibulocerebellum efferents?
To control eye movements and body equilibrium while standing or moving.
What is the general pattern for the efferents from cerebellar cortex?
Cerebellar cortex -> deep cerebellar nuclei -> superior cerebellar peduncle
What input goes to the Vermis?
Info about the neck and trunk
After processing input info, what nucleus recieves efferents from the Vermis?
The fastigial nucleus
Where does info go from the fastigial nucleus?
1. thalamus (VA/VL) to motor and premotor cortex
2. Brainstem to medial descending systems
What muscles recieve the efferent output from medial descending systems (ie Reticulospinal and Tectospinal)?
Axial and Proximal muscles - for balance remember?
2 functions of the vermis output:
1. Axial and proximal motor control
2. Control of ongoing execution of movements
What input goes to the Intermediate zone of the cerebellar hemispheres?
Input from the neck, trunk and limbs.
To what deep nucleus does the Intermediate zone project?
Interposed nuclei - Globose and Emboliform
Where do the interposed nuclei project?
1. Thalamas (VA/VL) to Motor and Premotor cortex
2. Brainstem to lateral descending pathways
What muscles recieve the efferent output of the intermediate zone and lateral descending systems?
Distal muscles
2 functions of the intermediate zone output:
1. Control of distal muscles
2. Ongoing execution of movement
To what deep nucleus does the Cerebrocerebellum project?
Dentate
Where does the dentate nucleus project to?
Red nucleus -> Thalamus -> Motor and premotor cortex
What are 2 tracts that carry info of the Cerebrocerebellum from the motor and premotor cortex?
1. Corticopontine tract
2. Corticospinal tract
What is the output from the cerebrocerebellum involved in?
Planning and mental rehearsal of complex motor actions.
Where does the cerebrocerebellum output from the pons go?
Back to the Dentate nucleus and the Cerebrocerebellum.
So what are the 3 general functions of the cerebellum?
1. Indirect regulation of movement and posture
2. Comparison of intentions with actual movements, and compensation for errors
3. Motor learning
How does the cerebellum indirectly regulate movement and posture?
By modulating the output of the major descending pathways
Where does the cerebellum recieve info about PLANS for movement from?
Motor and premotor cortex via the CORTICOPONTOCEREBELLAR TRACT
How does the cerebellum monitor the integration of descending and peripheral information regarding movement in the spinal cord?
Via the Ventral spinocerebellar tract
How does the cerebellum keep tabs on what's going on during movements?
Via feedback info from the sensory periphery
How does the cerebellum adjust output of the motor systems?
Via its projections to motor centers that send fibers to the spinal cord - like the Dentatorubrothalamic tract.