cerebellum

Question 1

function of

• vermis and intermediate cerebellum?
• lateral hemisphere of cerebellum?
• flocculonodular lobe?

Answer 1

• smooth motor execution
• motor planning/coordination
• posture/balance and eye gaze

Question 2

principle input to the flocculonodular lobe?

Answer 2

vestibular nuclei (VIII)

Question 3

major INPUT to the cerebellum travels in ____

Answer 3

inferior and middle cerebellar peduncle (ICP and MCP)

Question 4

major OUTFLOW from the cerebellum travels in ____

Answer 4

SCP

superior cerebellar peduncle

Question 5

topographical map layout in the cerebellum?

Answer 5

proximal/axial is middle and distal extremities as you move laterally

Question 6

vermis and intermediate zones get direct afferent info from____

Answer 6

contracting muscles by muscle spindles and golgi tendon organs –> dorsal roots of spinal nerves go up to cerebellum

Question 7

three layers of cerebellar cortex?

Answer 7

• -molecular layer (outer layer) - has parallel fibers
• -purkinje layer (middle/most important) –> all inputs to cerebellum fire purkinje cells and only purkinje axons leave the cerebellum
• -granule cell layer (innermost) - has golgi cells, granule cells, and glomeruli

Question 8

what is the only excitatory neuron in the cerebellar cortex?

Answer 8

the granule cell

Question 9

the only axons that leave cerebellar cortex?

Answer 9

purkinje axons

Question 10

what is the only excitatory neuron in the cerebellar cortex?

Answer 10

the granule cell

every other neuronal cell types are inhibitory (including purkinje!)

Question 11

the only axons that leave cerebellar cortex?

Answer 11

purkinje axons

Question 12

all of the inputs TO the cerebellar cortex are _____

Answer 12

excitatory

Question 13

two forms of afferents to the cerebellum?

Answer 13

• -mossy fibers - from motor cortex, vestibulocerebellar, spinocerebellar, and contricopontocerebellar systems
• -climbing fibers - come from inferior olivary nucleus (adjusts motor control)

Question 14

mossy fibers target and function

Answer 14

excitatory terminals on granule cells

use glutamate

Question 15

climbing fibers target and function

Answer 15

excitatory terminals on purkinje cells

Question 16

only pace climbing fibers come from

Answer 16

inferior olivary nucleus (olivocerebellar tract)

Question 17

mossy fibers target and function

Answer 17

excitatory terminals on granule cells
use glutamate
–only indirect influence on purkinje cells because they synapse on granule cells (g cells bifurcate into parallel fibers which then go synapse on purkinje cells)

Question 18

climbing fibers target and function

Answer 18

excitatory terminals on purkinje cells

—direct, powerful monosynaptic input to purkinje cell dendrites

Question 19

only pace climbing fibers come from

Answer 19

inferior olivary nucleus (olivocerebellar tract)

Question 20

on their way to the cerebellar cortex, the climbing and mossy fibers do what?

Answer 20

send excitatory collaterals to modulate deep cerebellar nuclei

Question 21

mossy and climbing fibers: direct or indirect effect on purkinje cells?

Answer 21

climbing = direct
mossy = indirect through granule cells and parallel fibers

Question 22

all output of the cerebellar cortex is _____ and mediated by _____

Answer 22

inhibitory; purkinje cells

Question 23

granule cells target transmitter and function?

Answer 23

purkinje cell
glutamate
excitatory

Question 24

purkinje cell target transmitter and function?

Answer 24

deep cerebellar nuclei
GABA
inhibitory

Question 25

golgi cell target transmitter and function

Answer 25

granule cell GABA inhibitory

Question 26

golgi cell target transmitter and function

Answer 26

granule cell GABA inhibitory

Question 27

deep cerebellar nuclei that receive purkinje cell synapses

Answer 27

fastigial nucleus interposed nuclei (emboliform and globose) dentate nucleus

Question 28

which deep nucleus recieves axons from the vermal region?

Answer 28

fastigial nucleus

Question 29

which deep nucleus receives axons from the paravermal regions?

Answer 29

embolifom and globose nuclei

Question 30

dentate nucleus receives axons from?

Answer 30

lateral hemispheres of cerebellum

Question 31

dentate nucleus receives axons from?

Answer 31

lateral hemispheres of cerebellum

Question 32

the right side of the cerebellum controls which side of body?

Answer 32

the right side controls muscles on the right side of the body BUT the pathway crosses over and back --purkinje axons from right side --> deep nuclei --> SCP (superior c. peduncle) --> CROSSES to opposite thalamus (left) --> left precentral gyrus (upper motor neurons) --> UMNs crosses back to right --> right side muscles

Question 33

cerebellar lesions on one side will affect muscles on the _____ side

Answer 33

ipsilateral