Exam IV Flashcards
what is the general function of the cerebellum? how does it work?
(1) detect erroneous movements and correct them
(2) receives sensory information and relays it’s influence on the motor system of the cortex and brain stem
what are the three major functions of the cerebellum?
(1) synergy of movement
(2) maintenance of upright posture
(3) maintenance of tone
what movement do the lateral and intermediate hemispheres of the cerebellum control?
limb movement
what movement do the vermis and floculonodular lobes control?
trunk movement
what do cerebellar lesions result in?
ataxia (irregular, uncoordinated movement)
what motor pathways are influenced by the lateral hemispheres of the cerebellum?
(1) lateral corticospinal tracts
what motor pathways are influenced by the intermediate hemispheres of the cerebellum?
(1) lateral corticospinal tracts
(2) rubrospinal tract
what motor pathways are influenced by the vermis and flocculonodular lobes of the cerebellum?
-Trunk Coordination
(1) anterior corticospinal tract
(2) reticulospinal tract
(3) vestibulospinal tract
(4) tectospinal tract
Balance & -Vestibuloocular reflexes
(1) medial longitudinal fasciculus
what is the order of cerebellar nuclei from lateral to medial?
Don’t Eat Greasy Foods
(1) Dentate
(2) Emboliform
(3) Globase
(4) Fastigial
where do each of the cerebellar nuclei receive input from?
(1) Dentate: lateral hemisphere
(2) Emboliform: intermediate hemisphere
(3) Globase: intermediate hemisphere
(4) Fastigial: vermis
where do climbing fibers of the cerebellum receive input from?
inferior olivary nucleus
where do mossy fibers of the cerebellum receive input from?
pontine nuclei
are mossy and climbing fibers excitatory or inhibitory on the cerebellar cortex?
excitatory
does ataxia due to a cerebellar lesion present ipsilaterally or contralaterally?
ipsilaterally
what does a lesion to the midline of the cerebellum cause?
(1) unsteady gait (truncal ataxia)
(2) eye movement abnormalities
what does a lesion lateral to the vermis cause?
limb ataxia (appendicular ataxia)
what do lesions to the cerebellum cause ipsilateral ataxia as opposed to contralateral ataxia?
the pathways are double crossed
what are the major cerebellar input pathways?
(1) pontocerebellar fibers
2) Spinocerebellar pathways (4 tracts
what information do the Dorsal spinocerebellar and Cuneocerebellar tracts carry?
unconscious proprioception of limb movements
what information does the Ventral spinocerebellar tract and Rostral spinocerebellar tract carry?
activity of interneurons within the spinal cord;
the Dorsal spinocerebellar tract relays information from what part of the body?
lower extremity
the Cuneocerebellar tract relays information from what part of the body?
upper extremity
what part of the spinal cord does the Ventral spinocerebellar tract relay information from?
lower region of the spinal cord
what part of the spinal cord does the Rostral spinocerebellar tract relay information from?
upper region of the spinal cord
is the dorsal spinal cerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Ipsilateral
(1) 1st synapse: in nucleus dorsalis of Clark
(2) 2nd synapse: ipsilateral lateral region of cerebellum
is the Cuneocerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Ipsilateral
(1) 1st synapse: external cuneate nucleus
(2) 2nd synapse: ipsilateral lateral region of cerebellum
is the Ventral spinocerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Double Crossed
(1) decussates: ventral commisure
(2) decussates: superior cerebellar peduncle
where does the superior cerebellar artery branch off of? what does it supply blood to?
(1) branches off the basilar artery
(2) superior region of the cerebellum
where does the anterior inferior cerebellar artery (AICA) branch off of? what does it supply blood to?
(1) branches off the basilar artery
(2) anterior inferior region of the cerebellum
where does the posterior inferior cerebellar artery (PICA) branch off of? what does it supply blood to?
(1) vertebral artery
(2) posterior inferior region of the cerebellum AND lateral medulla
what are some signs and symptoms associated with cerebellar artery infarcts?
(1) vertigo
(2) horizontal nystagmus
(3) limb ataxia
(4) unsteady gait
(5) HA
what impairments might an infarct of the AICA cause?
unilateral hearing loss (AICA supplies internal auditory artery)
what impairments might an infarct of the superior cerebellar artery cause?
ipsilateral ataxia (little to no brainstem involvement)
what are the signs of a cerebellar hemorrhage?
HA, ataxia, nystagmus, GI problems, CN IV palsy
what is the difference between dysrhythmia, DDD, and dysmetria?
(1) dysrhythmia: abnormal timing
(2) DDD: rapid alternating movements
(3) dysmetria: abnormal trajectories
what is false localization ataxia?
(1) ataxia caused by lesion outside of the cerebellum that involve cerebellar input or output pathways
what are a couple tests for appendicular ataxia?
(1) finger to nose
(2) heel-shin test
what is a test for truncal ataxia?
tandem gait
where does the basal ganglia send and receive information from?
the cortex
what is the primary function of the basal ganglia?
(1) planning, initiating, and executing movements
(2) helps maintain muscle control and postural control
what structure does the caudate nucleus and putamen make up?
striatum
what two structures make up the lenticular nucleus?
globius pallidus and putamen
how does the thalamus tell the body to move?
excitatory signals to the motor areas