Cerebellum - Lec11

Question 1

What are the basic function of the cerebellum?

Answer 1

Major role in timing of motor activities and in rapid, smooth progression from one muscle movement to the next:

• not essential for locomotion
• helps sequence motor activities
• moniters and makes corrective adjustments to motor activities while being exectutes
• actual movement vs intended movements
• kinesthetic memory
• enhances stretch relfex
• work with braistem for postural movements
• turns on antagonist at proper time
• programing of contraction

Question 2

What are the 3 lobes of the cerebellum?

Answer 2

Anterior lobe

posterior lobe

Flocculonodular lobe - vestibular system

Question 3

Which lobe of the cerebellum is evolutionary the oldest?

Answer 3

Flocculonodular lobe

Question 4

What are the folia?

Answer 4

The gyri of the cerebullum because they look like pages of a book

Question 5

What and where is the vermis? What is the function?

Answer 5

.vermis seperates the left and right hemishperes of the the cerebellum

Each hemisphere is divided into an intermediate zone and lateral zone

Function: control of muscle movements of the axial body, neck, shoulders and hips
(Posture)

Question 6

What are the general functions of the intermediate and lateral zones?

Answer 6

Intermediate: contraction in the distal portions of the upper and lower limbs
-hands, feet, fingers, toes

Lateral zone: association with the cerebral cortex and plannign of sequential motor movements

Question 7

What are the four pairs of deep cerebellar nuclei and what do lesion do to normal funciton?

Answer 7

Dentate 
Emboliform 
Globose 
-> lesions: extremeity ataxia ((all three above) 
Fastigial 
-> lesions: trunk ataxia

Question 8

What cells make upp the cerebullar cortex and their circuitry?

Answer 8

Granular layer
-granule cells, gogle type II cells and glomeruli
Purkinje cell layer
-purkinje cells
Molecular layer
-stellate cells, basket cells, purkinje dendrites, golgi type II cells and axons of granule cells

Question 9

Functional unit of the cerebellum

Answer 9

A single purkinje cells and a deep nuclear cell it projects too

Output is form a deep nuclear cell

Inputs also from climbing and mossy fibers

Question 10

What are pendular movements? How does the cerebellum effect pendular movements? /

Answer 10

Swinging back and forth

Cerebellum is good for stopping the body at the intended time (dampening) without the movemnts would overshoot

Question 11

What are ballistic movements?

Answer 11

movements that are so rapid they it’s not possible to receive feedback from cerebellum meaning they have to be preplanned

Question 12

What does the removal of the cerebellum do to movements of the body?

Answer 12

.causes movements to be slow to develop
Force develop is weak
Movements are slow to turn off

Question 13

Granular cells

Answer 13

Axons forms parallel fibers in cortex (+)

Question 14

Golgi cells

Answer 14

Project from parallel fibers to granular cell bodies (-)

Question 15

Basket cells

Answer 15

Project parallel fibers to purkinje axon hillock (-)

Question 16

Stellate cells

Answer 16

From parallel fibers to purkinje dendrites (-)

Question 17

What two cells provide laterall inhibition on purkinje cells?

Answer 17

Basket and stellate cells

Question 18

Vestibulocerebellum

Answer 18

Flocculonodular lobes and vermis
Control of balance and eye movemtns
Fibers incoming from vestibular system and oculomotor system
Output to vestibular system

Related to pendular movments

Question 19

Spinocerebellum

Answer 19

Vermis and intermediate zone
Synergic function: control of rate, force, range and direction of movemnt

Recieves: info from motor cortex and red nucleus about intended body movement plan
-feedback of what the actual movements are

Sends correctections to motor cortex through thalamus and magnocellular portion of red nucleus

Question 20

Cerebrocerebellum

Answer 20

Lateral parts of hemishperes
Associated with premotor, primary and association areas of the cerebral cortex

Recivees corticopontocerebellar projections

Coordination of skilled movement and speech

Plans a 1/10th of a second in advanced

Question 21

Afferent Tracts to cerebellum

Answer 21

Corticopontoocerebellar 
Vestibulocerebellar 
Reticulocerebellar
Spinocerebellar (ventral and dorsal) 
Olivocerebellar

Question 22

Dorsal spinocerebellar

Answer 22

From muscle spindles to ipilaterally in vermis andi ntermediate zones

• muscle contractions
• degree of tensio non the muscle spindles
• positions and rates of movements of parts of the body
• forces acting on surfaces of the body

Kinesthetic informaitaon

Question 23

Ventral spinocerebellar

Answer 23

terminates ipsilaterally and contralaterally

Signals from cortex through the corticospinal and rubrospinal tracts and internal motor pattern generators within the spinal cord

Gives cerebellum (is part of the cerebellum) information about which motor signals arrive at the anterior horns

Question 24

Olivecerebellar

Answer 24

Forms climbing fibers

Prom inferior olivary nuclei in medulle to purkinje cell dendrites (+) and to intracerebellar nuclei

Causes a prolonged AP on purkinje cells, one climbing fiber connects to 5-10 purkinje cells.

Question 25

Afferent tracts that form the ‘mossy’

Answer 25

Corticopontocebellar
Vestibulocerebellar
Reticulecerebellar
Spinocerebellar

Mossy fibers terminate on granule cells in the cerebellar cortex - excitory

Question 26

Which of the afferent tracts are the climbing fibers?

Answer 26

olivocerebellar

Question 27

Name the efferent tracts

Answer 27

Cerebelloreticular
Cerebelothalamocortical
Cerebellorubral
Cerebellovestibular

Question 28

Dysmetria and Ataxa

Answer 28

Symptoms of cerebellar disease

Brain cant tell how far away an object is and ofter overshoots movements and overcompensates- dysmetria- the difference resulting in uncoordinated movement -ataxia-

Question 29

Past pointing

Answer 29

Absence of cerebellum

Overreaching - difficulty in stopping a movement

Question 30

Dysdiadochokinesia

Answer 30

Inability to perform rapidly alterating movements

Question 31

Dysarthria

Answer 31

Inability to oordinate muscles to form words

Question 32

Cerebellar nystagmus

Answer 32

Flickering eye movements

Eye tremor, eye fixed off toward side

Question 33

Hypotonia

Answer 33

Reduced or loss of muscle tone