test 1: lecture 12

Question 1

The ___ cannot initiate movement but rather coordinates it.

Answer 1

cerebellum

Question 2

the cerebellum is separated from the cerebral hemispheres by ___

Answer 2

the tentorium cerebelli

Question 3

two main fissures of the cerebellum

Answer 3

primary fissure

posterolateral/caudolateral/uvulonodular

Question 4

three lobes of the cerebellum

Answer 4

• The anterior/rostral lobe
• The posterior/caudal lobe
• The flocculonodular lobe

Question 5

vermis

Question 6

The cerebellum consists of a midline vermis and two ___

Answer 6

hemispheres

Question 7

instead of sulci and gyri, cerebellum has

Answer 7

sulci

folia (little folds)

Question 8

•Projections of the white matter extend within the folia in a tree-like fashion termed the___

Answer 8

arbor vitae.

Question 9

three deep cerebellar nuclei

Answer 9

sit in the white matter of the cerebellum

–Dentate (lateral)–Interpositus–Fastigial

Question 10

how the cerebellum attatched to the rest of the brain

Answer 10

attached to brainstem by three paired cerebellar peduncles

inferior(caudal), middle and superior(rostral)

Question 11

•Rostral cerebellar peduncle connects to the ___

Answer 11

midbrain

Question 12

•Middle cerebellar peduncle connects to the ___

Answer 12

pons

Question 13

•Caudal peduncle connects to the ___

Answer 13

medulla oblongata

Question 14

10, 11, 12?

Answer 14

•Rostral peduncle (#12) connects to the midbrain

•Middle peduncle (#10) connects to the pons

•Caudal peduncle (#11) connects to the medulla oblongata

Question 15

layers of the cerebellum

Answer 15

–Molecular layer

–Purkinje cell layer

–Granular cell layer

(MPG)

Question 16

molecular layer of the cerebellum

Answer 16

outermost layer

no neurons, glial cells, neuronal processes

Question 17

purkinje cell layer of the cerebellum

Answer 17

2nd layer

neurons of purkinje cells live here

project dentrites into the molecular layer

send axon through granular layer→ white matter → synapse on cerebellar nucleus inside the white matter

Question 18

granular cell layer of the cerebellum

Answer 18

3rd layer

1000s of neurons

Question 19

where do purkinje fibers synapse?

Answer 19

neurons of purkinje cells live here

project dentrites into the molecular layer

send axon through granular layer→ white matter → synapse on cerebellar nucleus inside the white matter

Question 20

white arrows?

Answer 20

purkinje cells of the cerebellum

(below is the granular cell layer)

(above is the molecular layer)

Question 21

1.All afferent fibers to the cerebellar cortex (mossy and climbing) are ___

Answer 21

excitatory.

Question 22

___ are excited by climbing and mossy fibers; they are inhibited by interneurons from the cortex.

Answer 22

1.Purkinje cells

Question 23

Outgoing fibers from the cerebellar cortex are axons from Purkinje cells. They are ___

Answer 23

inhibitory

Question 24

Neurons of the ___ nuclei and the ___ nuclei receive inhibitory projections from Purkinje cells.

Answer 24

cerebellar

vestibular

Question 25

1.Neurons of the cerebellar nuclei are \_\_\_

Answer 25

excitatory

Question 26

Cerebellar nuclei projections can be\_\_\_

Answer 26

excitatory or silent but **not inhibitory.**

Question 27

All ___ fibers to the cerebellar cortex (mossy and climbing) are excitatory

Answer 27

afferent

Question 28

how do mossy fibers work?

Answer 28

mossy from brainstem and spinal cord → granule neurons → purkinje cells **excitatory** **Mossy fibers,** from the brainstem and spinal cord, have collaterals which synapse on cerebellar nuclei with the main axon terminating on **granule neurons.** Axons of granule neurons synapse on **Purkinje cells.**

Question 29

**\_\_\_** from the brainstem and spinal cord, have collaterals which synapse on cerebellar nuclei with the main axon terminating on granule neurons.

Answer 29

**Mossy fibers,**

Question 30

how do climbing fibers work?

Answer 30

directly synapse on purkinje cells ## Footnote Climbing fibers, from the **olivary nucleus**, enter through the **caudal cerebellar peduncle**. They have collaterals which synapse on cerebellar nuclei with the main axon **terminating on Purkinje neurons.**

Question 31

Climbing fibers, from the ____ , enter through the ___ **cerebellar peduncle**. They have collaterals which synapse on cerebellar nuclei with the main axon **terminating on Purkinje neurons.**

Answer 31

**olivary nucleus** **caudal**

Question 32

climbing fibers come from where and go where?

Answer 32

olivary nucleus synapse on Purkinje neurons in the cerebellum

Question 33

what cells are inhibitory to purkinje cells?

Answer 33

stellate neurons (interneurons) | (outer 1 , basket 2, golgi cells 3)

Question 34

\_\_\_ are cerebellar afferent pathways with general proprioception information

Answer 34

Spinocerebellar(unconscious proprioception) cuneocerebellar tracts (upper limb unconscious proprioception) **lower limb = dorsal spinocerebellar** → sensory into spinal cord → synapse in dorsal horn (clarks nucleus) → up to the cerebellar cortex **by mossy fibers** **upper limb= cuneocerebellar tract** → sensory into spinal cord → synapse in accessory cuneate nucleus in the brain stem→ up to cerebellar cortex **by mossy fibers** **both are ipsilateral (same side)**

Question 35

Vestibulocerebellar tracts with vestibular information are delivered by \_\_\_

Answer 35

mossy fibers type of afferent cerebellar pathway

Question 36

\_\_\_ tracts with visual and auditory information are carried by mossy fibers to the cerebellum

Answer 36

Tectocerebellar ## Footnote **afferent pathway**

Question 37

what are some cerebellar afferent pathways from upper motor neuron fibers?

Answer 37

Rubrocerebellar Reticulocerebellar Olivocerebellar→ Climbing fibers Cerebropontocerebellar (pyramidal) →Mossy fibers

Question 38

information from the olivocerebellar travel to the cerebellum by \_\_\_

Answer 38

climbing fibers

Question 39

All outgoing fibers from the \_\_\_cortex are axons from Purkinje cells that are inhibitory.

Answer 39

cerebellar

Question 40

Purkinje cells project to the ___ nuclei. Efferent axons from the cerebellar nuclei project to the brainstem and are \_\_\_. Some axons from Purkinje cells of the flocculonodular lobe project directly to the ___ nuclei.

Answer 40

cerebellar excitatory. vestibular **purkinje→ cerebellar nuclei are always inhibitory** **cerebellar nuclei → brainstem are excitatory**

Question 41

In general, cerebellar efferent fibers do not project to the spinal cord but rather control motor activity by influencing \_\_\_pathways.

Answer 41

upper motor neuron **cerebellar cortex (purkinje cells) inhibitory → cerebellar nucleus** **cerebellar nucleus excitatory → brain stem (thalamus, midbrain, medulla/pons)**

Question 42

how does cerebellum control movement

Answer 42

brain tells body to move → muscle fibers at same time those same **upper motor neurons** will tell cerebellum we are moving through the **olivary nucleu**s and **pontine nucleus** the cerebellum will get information about proprioception from **dorsal spinocerebellar and cuneocerebellar tracts** cerebellum takes this information and transfers back to brainstem and brain by **cerebellar nucleus** → **red nucleus** → thalamus → **motor cortex (telencephalon)** **lets make this smooth and controlled motion**

Question 43

two primary functions of the cerebellum

Answer 43

* Coordinate and regulate movement * Control of posture

Question 44

The ___ (archicerebellum) is confined to the ventral aspect of the cerebellum.

Answer 44

**vestibulocerebellum**

Question 45

The \_\_\_\_(paleocerebellum) constitutes the midline.

Answer 45

**spinocerebellum**

Question 46

The \_\_\_\_(pontocerebellum; neocerebellum) is predominantly the hemispheres.

Answer 46

**cerebrocerebellum**

Question 47

princible sign of cerebellum dysfunction

Answer 47

ataxia

Question 48

what part of the cerebellum is associated with balance

Answer 48

vestibulocerebellum flocculonodular lobe

Question 49

problems with the vestibulocerebellum:

Answer 49

disturbance of equilibrium (loss of balance)

Question 50

issues with the spinocerebellum results in \_\_\_

Answer 50

– hypertonus and exaggeration of postural reflexes (swaying side to side)

Question 51

issues with the cerebrocerebellum results in \_\_

Answer 51

asynergia; dysmetria, tremor, hypotonia **disease will be same side as tremor**

Question 52

how to test for issues with the vestibulocerebellum and spinocerebellum

Answer 52

tandem gait; observing for nystagmus and truncal ataxia.

Question 53

how to test for cerebocerbellum issues

Answer 53

finger to nose, rebound, speech (dysarthria- uneven voice)

Question 54

with cerebellum issues

Answer 54

ataxia. dsymetria (overstepping, understepping) **same side deficits** menace= wont blink when stimulated intention tremors