Quiz 5 Cerebellum

Question 1

Cerebellum integrates very rapidly a host of sensory input info. on the momentary status of:

Answer 1

Muscle contraction
joint tension
Visual & auditory input on the equilibrium

Question 2

Integration allows the cerebellum to aid & influence:

Answer 2

Muscle tone
Posture
Aids in making skilled somatic muscle movements smooth and effective

Question 3

True or False Input fibers come from ALL CNS levels (M.O., pons, midbrain, diencephalon & telencephalon)

Answer 3

True

Question 4

T/F Each cerebellar hemisphere influences the ipsilateral side of the body

Answer 4

True

Question 5

The cerebellum is attached to the Medulla Oblongata via:

Answer 5

Inferior cerebellar peduncle

Question 6

The cerebellum is attached to the Pons via:

Answer 6

Middle cerebellar peduncle

Question 7

The cerebellum is attached to the Midbrain via:

Answer 7

Superior cerebellar peduncle

Question 8

Inferior peduncle:

Answer 8

Afferent fiber dominate (into cerebellum)(Post. spinocerebellar & cuneucerebellar fiers)
Efferent are also present

Question 9

Middle peduncle:

Answer 9

Afferent fibers only

All fibers going in cerebellum coming from pontine nuclei

Question 10

Superior peduncle:

Answer 10

Efferent fibers are dominate

Afferent fibers are present (Ant. spinocerebeller fibers)

Question 11

Which brain tumors are most frequent in male children over female children?

Answer 11

Medulloblastomas

arise in the superior meduallry velum as well as the posterior part of the cerebellar vermis

Question 12

External subdivisions of cerebellum:

Answer 12

Median: Vermis
Lateral: rt/lt hemisphere

Question 13

The vermis & the hemispheres are divided into lobes which are named:

Answer 13

Anterior
Posterior
Flocculonodular

Question 14

White matter collectively is known as:

Answer 14

Corpus Medullare

Question 15

White matter is primarily made up of 4 different fibers:

Answer 15

1. Afferent projection fibers (carrying info. going TOWARDS cerebellum)
2. Efferent projection fibers (carrying info. FROM cerebellum
3. Commissural fibers (crossing the midline- connecting each side)
4. Association fibers (carrying info. from one part of cerebellum to the other)

Question 16

Most common NEURON cell types:

Answer 16

1. Purkinje neurons
2. Golgi II neurons
3. Stellate neurons
4. Basket neurons
5. Granular neurons

Question 17

The 5 neuron cells are arranged into 3 laminae:

Answer 17

Outer: Molecular layer
Middle: Purkinje Cell body layer
Inner: Granular layer

Question 18

Two types of outside axons bring input in cerebellar cortical laminae:

Answer 18

Mossy fibers

Climbing fibers

Question 19

Purkinje fibers are the fibers taking messages ____ from the cerebellar cortex

Answer 19

AWAY

Question 20

• Middle cortical lamina

- Composed of 30 million purkinje neuron cell bodies that reach out into the molecular layer

Answer 20

Purkinje cell layer

Question 21

________ purkinje axons are the only efferent (outgoing) fibers from the cerebellar cortex. Most of these terminate in the deep central _______ _____. Some bypass to end in Deiters’ portion of the ________ ______.

Answer 21

Myelinated
cerebellar nuclei

Vestibular nucleus

Question 22

Neurotransmitter released by the Purkinje axon is ________ to its target site.

Answer 22

INHIBITORY (GABA)

Question 23

• Innermost cortical lamina

- Layer is named for the abundance of small granular neurons that are present.

Answer 23

Granular Layer (lamina)

Question 24

Granular cell dendrites are ________ by incoming _____ ______. The axon from each granular cell ascends into the molecular layer where it ________ & makes synapse with the spined branches of the purkinje cell dendrites.

Answer 24

Stimulated
Mossy fibers
Bifurcates

Question 25

Neurotransmitter from the granular neuron is:

Answer 25

Glutamate (most abundant neurochemical) | Stimulating the purkinjes

Question 26

Mossy fibers mostly originate from the:

Answer 26

Spinocerebellar & corticopontocerebellar sources

Question 27

Theses fibers are excitatory & synapse with granular cell dendrites:

Answer 27

Mossy Fibers

Question 28

Granular cell axons ascend to synapse with ______ ______ of purkinje cells in the ______ _____. These cells are _______ to the purkinje cells Glutamate)

Answer 28

Spined dendritic branches Molecular layer Excitatory

Question 29

Purkinje cell axons _______ (inhibit) the deep central cerebellar nuclei. If the purkinje cell is NOT excited (firing), then the inhibitory results are minimal. _____ is the neurotransmitter.

Answer 29

Influence | GABA

Question 30

- Extremely excitatory- reaching the Purkinje cells smooth dendritic branches directly - Fibers generally originate in the inferior olivary nucleus (pontine nuclei & reticular cells may also contribute)

Answer 30

Climbing fibers

Question 31

Neurotransmitter involved with Climbing fibers:

Answer 31

Aspartate

Question 32

_______ & _____ fibers bring _______ outside input to the cortex of the cerebellum. This input is integrated trough the granular, ____, basket, _______, & Purkinje cells. Info. leaves the cerebellar cortex through _______ axons. The major target for this ________ outflow is the deep or central cerebellar nuclei.

Answer 32

``` Climbing & mossy Excitatory stellate Purkinje cells Purkinje axons INHIBITORY ```

Question 33

Names for the central nuclei (arranged most lateral to most medial):

Answer 33

1. Dentate (largest / most lateral) 2. Emboliform 3. Globose 4. Fastigial- Most primitive & medial

Question 34

The emboliform & globose collectively are referred to as the:

Answer 34

Interposed nuclei

Question 35

Purkinje axons from the cortex of the:

Answer 35

Vestibulocerebellum Spinocerebellum Cerebrocerebellum

Question 36

Go to the Vestibular nucleus & release GABA

Answer 36

Vestibulocerebellum

Question 37

Go to the Interposed nucleus & fastigial nucleus:

Answer 37

Spinocerebellum

Question 38

Go to the Dentate Nucleus

Answer 38

Cerebrocerebellum

Question 39

Fastigial Nucleus fibers exit the _______ cerebellar peduncles to terminate in the ______ nucleus, reticular formation & nuclei for C.N ___, ___, ___

Answer 39

Inferior cerebellar peduncles Vestibular nucleus III, IV, & VI

Question 40

______ nucleus axons generally extend to the ____ Nucleus & reticular formations via the superior cerebellar peduncles

Answer 40

Interposed | Red

Question 41

_____ axons generally reach the ______ with collateral branches being sent to the Red nucleus (Once again via the superior cerebellar peduncles)

Answer 41

Dentate | Thalamus

Question 42

The right side of the cerebellum only deals with the right side of the body (vice versa). Naturally bilateral lesions involve bilateral symptoms

Answer 42

Create ipsilateral clinical signs

Question 43

________ disturbances are quite common. This is particularly true from lesions in the Archicerebellar lobe (Flocculonodular syndrome- Where the patient must constantly fight against falling backwards)

Answer 43

Equilibrium Disturbances

Question 44

_______ ____ changes are common signs. In rare instances electrical stimuli have been applied to the cerebellar cortex to relieve hypertonicity

Answer 44

Muscle tone changes

Question 45

_____ (lack of order or coordination) is not limited to any lobe, but most frequent in lesions of the neocerebellum. One might stagger to the side vs. falling backward in the flocculonodular syndrome. Inability to rapidly supinate/ pronate hands

Answer 45

Ataxia

Question 46

Common symptom in which measured movements are difficult to make. You generally over or undershoot your target

Answer 46

Dysmetria