Flashcards
NS 21 - cerebellum and basal ganglia
Cards in this deck (26)
- 1which fossa is the cerebellum located inposterior cranial fossa
- 2what is the sheet of dura mater that covers the cerebellum and separates it from the cerebrum called?tentorium cerebelli
- 3what is the falx cerebri?it is a reflection of dura mater that divides the cerebral hemispheres
- 4what structure divides the cerebellum into 2 lobes?the vermis
- 5at which points does the cerebellum join the brainstem?superior cerebellar peduncle - midbrain
middle cerebellar peduncle - pons
inferior cerebellar peduncle - medulla - 6what are the 3 functional lobes of the cerebellum?cerebrocerebellum
spinocerebellum
vestibulocerebellum - 7cerebrocerebelluma.k.a. neocerebellum
formed by lateral hemispheres
plans + coordinates movements
dentate nucleus is here - 8spinocerebelluma.k.a paleocerebellum
formed by the vermis (midline)
concerned with muscle tone and posture
nuclei globose and emboliform are here - 9vestibulocerebelluma.k.a archicerebellum
formed by flocculonodular lobe
concerned with balance
fastigial nucleus is found here - 10why are problems of the cerebellum ipsilateral?there is a double decussation
- 11midline lesions affect which functional lobe(s) of the cerebellum? what are the consequences?vestibulocerebellum and spinocerebellum affected
therefore you get nystagmus, loss of balance, disturbed + unsteady gait - 12lateral lesions affect which function lobe(s) of the cerebellum? what are the consequences?cerebrocerebellum affected
therefore you get incoordination/intention tremor, unsteady gait
(no sensory deficit and no muscular weakness) - 13bilateral dysfunction of the cerebellum presents withdysarthria (unclear articulation of speech)
cerebellar ataxia (incoordination of both arms, wide-based unsteady gait) - 14what is the significance of the cerebellar tonsil position within the skull?they lie just above foramen magnum and so if a lumbar puncture is done to a patient with increased ICP they can herniate out, compressing the medulla --> disrupting normal HR, BP, breathing --> death
- 15state the names of the 6 basal ganglia nulceinucleus accumbens
caudate nucleus
putamen
globus pallidus
subthalamic nucleus
substantia nigra - 16what makes up the corpus striatum?caudate nucleus + putamen + globus pallidus
- 17what makes up the lentiform/lenticular nucleus?putamen + globus pallidus
- 18what are the 2 parts of the substantia nigra and which part produces dopamine?pars compacta - dopamine
pars reticulata - 19what are the 2 most important pathways in the basal ganglia and what are their functions?direct pathway allows purposeful movements
indirect pathway prevents unwanted movements - 20inputs to direct/indirect pathways fromcortex mainly
thalamus
substantia nigra (dopamine) - 21outputs from the striatum go toglobus pallidus (internal segment) and pars reticulata of substantia nigra
cortex (primary and supplementary motor regions) and UMNs (via the thalamus) - 22pathophysiology of Huntington's disease?neuronal loss in the striatum and cortex (frontal and parietal lobes)
- 23what is chorea?brief sudden purposeless jerks
- 24age of onset of Huntington'sbetween 20-50 years
- 25what is hemiballismusa rare movement disorder (a type of chorea) that results in flailing, ballistic, and undesired movement of limbs
- 26hemiballismus is caused bylesion in contralateral subtalamic nucleus
(can be due to MS)