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Flashcards in NMP DUKE midterm Deck (50):
1

Cerebellum

is folded under the occipital lobe; if opened, you can see the vermis along the midline,
surrounded by the paravermis (intermediate lobe) and the lateral hemisphere/lobe

2

Horizontal fissure

runs along lateral side of the cerebellum

3

Cerebellum specialty

it specializes in coordination of motor activity; it does not initiate or control movement

4

(3) Cerebellum
major regions

1. Archicerebellum (vestibulocerebellum)
2. Paleocerebellum (spinocerebellum)
3. Neocerebellum (corticocerebellum)

5

Vermis

long, narrow, midline structure with many crimps; terminates as the uvula

Primary fissure = deepest fissure of
the vermis

6

Archicerebellum

vermis + paravermis; the middle region; remember the spinocerebellar tracts terminate in the vermis & paravermis (paravermis = intermediate lobe)

7

Neocerebellum

lateral hemispheres/lobes; it develops with
the neocortex

8

Function of Neo + Paleo

coordination of muscles for the purpose of
movement

9

The vermis & paravermis (termination of cerebellar tracts) contain

broken somatotopic map

vermis---Axial skeleton
paravermis---Extremities

10

Two differences of cerebellar somatotopic map
from neocortical somatotopic map

1.Adjacent parts of the body are not perfectly
in line with each other; the representation is topsy
-turvy
2. Body parts may be represented multiple times;
there could be two index fingers, or two forearms; this is because there are many cerebellar tracts entering, each bringing a map , and they don't overlap perfectly

11

cerebellar white matter

arbor vitae

12

Layer 1

molecular layer

13

layer 2

purkinje layer (main cells)

14

layer 3

granular layer

15

Purkinje cells

main neurons of cerebellum
There is one giant dendrite that bifurcates endlessly, but it sends out only one axon,
which terminates on a group of cells deep
in the white matter

16

where do purkinje fibers terminate?

deep cerebellar nuclei

17

What is the arrangement of the entire
cerebellum?

purkinje---->deep cerebellar nuclei----->out of cerebellum

18

Main afferents of the cerebellum

the mossy/parallel fiber system

19

Rosette

cluster of mossy fibers and granule cells together

20

Climbing fibers

cerebellar afferent fibers that don't go to granule cells in rosettes

21

Where do climbing fibers go?

straight to the surface and split to synapse on the purkinjes

22

Where do climbing fibers come from?

climbing fibers are axons from the inferior olive (olivocerebellar fibers)

23

Where do climbing fibers enter the cerebellum?

inferior peduncle

24

T or F
climbing and parallel fibers are excitatory to the purkinjes?

T

25

purkinje firing rate----normal

70 AP/sec

26

purkinje firing rate-----excited

150-200 AP/sec

27

T or F
purkinje cells are excitatory on deep cerebellar nuclei.

F
inhibitory

28

T or F
deep cerebellar nuclei are excitatory on everything outside the cerebellum.

F
inhibitory

29

T or F
If the deep cerebellar nuclei are stimulated by purkinje cells the will inhibit the outside the cerebellum.

F
purkinje inhibit deep cerebellum nuclei which excites the outside through double inhibition

30

Three (3) other important cells of the cerebellum

1. basket
2. stellate
3. golgi

31

Are the three other cells inhibitory or excitatory to the perkinjes?

inhibitory

32

Basket cell

axon comes out and cups the base of
the purkinje, right where the purkinje axon
comes out

33

Stellate cell

found right outside the purkinje's dendrite
and shuts it off at this location

34

Golgi cell

sends axon to rosettes, the granule cells, to stop the purkinje from receiving any signals in the
first place
.
They do not send axons directly to the purkinje, but
they still shut it down

35

Deep cerebellar nuclei of each region of cerebellum
Corticocerebellum

1. receives from entire neocortex, especially areas 4, 6, and 3,1,2
2. entire middle cerebellar peduncle is comprised of "corticopontocerebellar" tracts

Axons end on purkinjes→dentate nucleus→VLc→
area 4 (some 6)

36

Deep cerebellar nuclei of each region of cerebellum
spinocerebellum (paleo)

(the paravermis and vermis send to different deep cerebellar nuclei)

1. vermis-sends axons to a different deep nucleus, the fastigial nucleus (most lateral deep nucleus)

2.paravermis---sends to n.interpositus= formed by two separate classes of neurons (makes two nuclei) globose and emboliform nuclei; these are the deep nuclei of the paravermis; they send to RNmc

37

Deep cerebellar nuclei of each region of cerebellum
Vestibulocerebellum (archi)

he deep nucleus it uses is not its own; it shares the fastigial n. with the vermis but only 20% of axons go here; most axons go to the vestibular nuclei in the pons

38

Descending Tracts

to affect a muscle, they must hook up to somatic-α
motor neurons in lamina IX; most end on interneurons in lamina VIII and then relay to IX

39

Descending Tracts
Lateral vestibulospinal
from

vestibular nuclei

40

Descending Tracts
Lateral vestibulospinal
integrating by means of

it is one of few tracts whose axons send collaterals to multiple segments, integrating
segments together

41

Descending Tracts
Lateral vestibulospinal
excite

axons excite somatic-α motor neurons,especially
in segments controlling extremity extensors

42

Descending Tracts
Lateral vestibulospinal
main function

so the main function is anti-gravity;
it stabilizes you in space by increasing
muscle tone

43

Descending Tracts
Lateral vestibulospinal
vestibulospinal reflex

when you lose support underneath you (or when you're free falling), you extend all your extremities to try to maintain balance in the air

44

Descending Tracts
Lateral reticulospinal (medullary)
from

from the reticular formation; n.reticularis gigantocellularis

45

Descending Tracts
Lateral reticulospinal (medullary)
main funtion

this goes to motor neurons of extensors to inhibit extensor muscles

46

Descending Tracts
Medial reticulospinal (pontine)
from

from the reticular formation; n.
reticularis pontis

47

Descending Tracts
Medial reticulospinal (pontine)
first function

axons go primarily to segments controlling axial extensors, especially postural support mm. in the neck

48

Descending Tracts
Medial reticulospinal (pontine)
second function

axons also go to phrenic nucleus(lamina IX of C3
-C5) to control diaphragm/respiration; specifically, it is involved in phasic functions of respiration

49

Descending Tracts
Medial reticulospinal (pontine)
third function

this tract is also involved in initiation and speed of locomotion (walking)

50

Descending Tracts
MLF
general

medial longitudinal fasciculus;most medial and primitive tract