473 post MT 2 Flashcards
primary sensory cortex
primary motor cortex
localize and identify what and where sensory stimuli are
trigger and execute motor commands
what does the motor-association cortex consist of + functions?
premotor cortex-lateral surface
supplimentary motor area-superior and medial surface
involved in formulating motor programs for complex movements
premotor cortex functions
- involved in activating multiple mm in the limb
- most activation prior to start of movement (ie involved in planning)
- directionally specific-affects contralateral limbs
-lesions result in: inability to initiate multi-joint movements and coordinating the limb
supplementary motor area
- complex sequences of movements
- bilateral coordination of movement
- affects contra-lateral limbs
- affects proximal muscles directly and distal muscles indirectly via primary motor cortex
- has interhemispheric connections b/t the two sides
supplementary motor area lesions
- difficulty planning complex movements (apraxia)
- deficits in coupling voluntary movements with postural adjustments
dominant hemisphere
L parietal lobe and L hemisphere has a particular role in coordinating and planning movements-particularly w/a tool or interacting w/the environment
damage to which areas might result in apraxia?
motor association areas (ie supplementary or premotor)
parietal association cortex of dominant hemisphere
hemispatial neglect
damage to RIGHT (non dominant) parietal association cortex or frontal cortex
-inability to attend to sensory cues on the contralateral side
4 types of hemi-neglect
sensory
motor-intentional
combination motor and sensory
conceptual (how things are represented)
what is the test for hemi-neglect?
test for extinction -motor -tactile touch on one side ,then both at once -will neglect L side things, movements disappear or decrease during bilateral movements (they are attending to things on the R side)
conceptual neglect
two types
anosognosia-no awareness of hemi-neglect
hemiasomatognosia-no awareness of side of body-limbs “dis-owned”
which side would a patient have trouble dressing on if they have apraxia due to a R parietal lesion?
LEFT
alien hand cause
damage to corpus collosum and/or supplementary motor area of non dominant hemisphere
-hand is out of control and acts autonomously
what separates the lobes of the cerebellum?
primary fissure-anterior and posterior
postero-lateral fissure-separates flocculo-nodular lobe
functional regions of cerebellum
- vermis-down center
- intermediate-medial 1/3
- lateral-lateral 2/3
- flocculo-nodular
dentate nucleus
cerebellum, lateral zone
interposed nucleus
cerebellum, intermediate zone
-composed of globous and eboliform
fastigial nucleus
cerebellum, vermis and flocculonodular zones
what is different from the cerebrum to cerebellum about how information is carried two and from?
all info to cerebellum travels via cerebellar peduncles
cerebral peduncles go to ventral region of midbrain
which cerebellar peduncle carries mostly outputs?
inputs?
out-superior
in-middle and inferior
pontocerebellar fibers
- cortico-pontine fibers from cortex to pontine nuclei
- ponto-cerebellar fibers cross midline and enter cerebellum via middle peduncle
- efferent copy of motor commands for voluntary movement
spinocerebellar pathways
leg proprioceptors:via dorsal spinocerebellar tract though nucleus dorsalis of clark
arm proprioceptors: through cuneocerebellar tract via external cuneate nuclues
-ie super similar to PCML(the nuclei receive PCML inputs) but nucleus gracilis is nucleus dorsalis of clarke
via inferior cerebellar peduncle
vestibular inputs to cerebellum
-primary vestibular afferents plus projections from vestibular nuclei go to ipsilateral cerebellum via inferior cerebral peduncle’s juxtarestiform body
outputs from lateral cerebellar hemispheres
fibers origionate in lateral hemispheres (involved in motor planning)
travel from dentate nucleus, axons exit through superior cerebellar peduncle, cross at midbrain and continue to contralateral thalamus
-thalamus to widespread areas of the cortex: premotor cortex, SMA, motor cortex, parietal cortex