cerebellum Flashcards
function of
- vermis and intermediate cerebellum?
- lateral hemisphere of cerebellum?
- flocculonodular lobe?
- smooth motor execution
- motor planning/coordination
- posture/balance and eye gaze
principle input to the flocculonodular lobe?
vestibular nuclei (VIII)
major INPUT to the cerebellum travels in ____
inferior and middle cerebellar peduncle (ICP and MCP)
major OUTFLOW from the cerebellum travels in ____
SCP
superior cerebellar peduncle
topographical map layout in the cerebellum?
proximal/axial is middle and distal extremities as you move laterally
vermis and intermediate zones get direct afferent info from____
contracting muscles by muscle spindles and golgi tendon organs –> dorsal roots of spinal nerves go up to cerebellum
three layers of cerebellar cortex?
- -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
what is the only excitatory neuron in the cerebellar cortex?
the granule cell
the only axons that leave cerebellar cortex?
purkinje axons
what is the only excitatory neuron in the cerebellar cortex?
the granule cell
every other neuronal cell types are inhibitory (including purkinje!)
the only axons that leave cerebellar cortex?
purkinje axons
all of the inputs TO the cerebellar cortex are _____
excitatory
two forms of afferents to the cerebellum?
- -mossy fibers - from motor cortex, vestibulocerebellar, spinocerebellar, and contricopontocerebellar systems
- -climbing fibers - come from inferior olivary nucleus (adjusts motor control)
mossy fibers target and function
excitatory terminals on granule cells
use glutamate
climbing fibers target and function
excitatory terminals on purkinje cells
only pace climbing fibers come from
inferior olivary nucleus (olivocerebellar tract)
mossy fibers target and function
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)
climbing fibers target and function
excitatory terminals on purkinje cells
—direct, powerful monosynaptic input to purkinje cell dendrites
only pace climbing fibers come from
inferior olivary nucleus (olivocerebellar tract)
on their way to the cerebellar cortex, the climbing and mossy fibers do what?
send excitatory collaterals to modulate deep cerebellar nuclei
mossy and climbing fibers: direct or indirect effect on purkinje cells?
climbing = direct mossy = indirect through granule cells and parallel fibers
all output of the cerebellar cortex is _____ and mediated by _____
inhibitory; purkinje cells
granule cells target transmitter and function?
purkinje cell
glutamate
excitatory
purkinje cell target transmitter and function?
deep cerebellar nuclei
GABA
inhibitory
golgi cell target transmitter and function
granule cell
GABA
inhibitory
golgi cell target transmitter and function
granule cell
GABA
inhibitory
deep cerebellar nuclei that receive purkinje cell synapses
fastigial nucleus
interposed nuclei (emboliform and globose)
dentate nucleus
which deep nucleus recieves axons from the vermal region?
fastigial nucleus
which deep nucleus receives axons from the paravermal regions?
embolifom and globose nuclei
dentate nucleus receives axons from?
lateral hemispheres of cerebellum
dentate nucleus receives axons from?
lateral hemispheres of cerebellum
the right side of the cerebellum controls which side of body?
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
cerebellar lesions on one side will affect muscles on the _____ side
ipsilateral
