NEURO LEC 19 CEREBRAL CORTEX Flashcards
What are the 3 kinds of gray matter in the cortex?
Granular
Pyramidal
Interneurons
True or false: the cortex has a cellular layer and a purkinje layer
False
What is the major output cell of the cortex?
Pyramid cells
Each layer of the cortex has 6 layers except….
Olfactory and medial temporal corticies, they have 3
True or false: motor and sensory neurons extend down to the sulcus of the gyrus
True
Brodmann’s areas are particularly helpful during __________
Surgical techniques and research (measure cortical activity)
Primary somatosensory cortex -> Secondary somatosensory cortex -> _______________________ -> _____________________ -> Primary motor cortex
Association cortex
Motor planning areas
what part of the cortex sends descending motor signals?
Primary motor cortex
What part of the corticies differentiates intensity and qualities of sensory info?
Primary sensory areas
What part of the cortex handles more complex sensory processing
secondary sensory cortex
Where is the primary somatosensory cortex found?
Postcentral gyrus
Where is the auditory cortex found?
Within lateral fissure and superior temporal lobe
What cortex is found within calcarine sulcus and adjacent gyri
visual cortex
What cortex is found within posterior end of lateral fissure and parieto-insular cortex
Vestibular cortex
Which part of the visual cortex analyzes color and movements?
Secondary visual cortex
The secondary visual cortex projects to the _____________ to guide visual fixation keeping item in central vision
superior colliculus
what cortex constrasts sounds heard from memories and categorizes them?
Secondary auditory cortex
1
secondary somatosensory cortex
2
secondary visual cortex
3
secondary somatosensory cortex
4
secondary visual cortex
5
secondary auditory cortex
A lesion to the secondary somatosensory cortex causes what?
astereognosis
A lesion to the secondary visual cortex causes what superiorly and what in the middle portion?
Superiorly: optic ataxia
Middle portion - Visual agnosia
Lesion to the secondary auditory cortex causes what?
auditory agnosia
What cortex is responsible for discriminating shapes, texture, size
primary somatosensory
The secondary somatosensory cortex projects to __________ and _________
Motor and limbic areas
what cortex has the highest degree of convergent somatosensory info?
Posterior parietal cortex
note: it’s a secondary sensory and association cortex
Outputs of the _____________ are critical for integration of sensory and motor info
posterior parietal cortex
The primary auditory cortex does what?
Allows awarenes of intensity and sounds
the primary auditory cortex receives info from the cochlea of both ears through pathways that synapse in the ___________ and _______________ (thalamus)
inferior colliculus -> medial genticulate body
True or false: The vestibular cortex is well defined
False, not well defined
Some sources have primary vestibular cortex in only _____ hemisphere and some evidence says its in both hemispheres
right
What are the two streams of the secondary visual cortex
action stream (dorsal)
-adjusts limb movement
perception stream (ventral)
-recognizes objects
The secondary visual cortex perception stream runs where?
ventrally to temporal lobe
The secondary visual cortex dorsal stream runs where?
dorsally through posterior parietal cortex to frontal lobe
1
Medial dorsal prefrontal cortex
perceives others emotions/beliefs
2
ventral prefrontal cortex
-mood and affect
3
parietotemporal association lobe
-intellegence (includes wernicke)
Wernicke’s area is contained in what cortex
parietotemporal association cortex
What cortex is involved in intellegence, problemsolving, and understanding communication
parietotemporal association cortex
What does the dorsolateral prefrontal cortex do?
self awareness/executive functions
remember, it’s dorsal bc you have to take a step back and observe yourself to have self awareness
The premotor cortex contains ________% corticospinal neurons especially from trunk and shoulder
20-30
what cortex is for anticipatory postural adjustments?
pre-motor cortex
What cortex is for motor planning, mvmt initiation
supplementary motor cortex
what cortex controls CONTRALATERAL fractionated movement?
primary motor cortex
remember it’s contralateral bc the corticospinal tract is contralateral
The source of most corticospinal tract neurons is in the……
primary motor cortex
damage to what cortex causes flexion or extension synergies?
primary motor
bc you lose the ability to do fractionated movement
What is prosopagnosia
Disorder of ventral visual stream
inability to recognize faces
Disorders of _____________ can cause visual object agnosia
ventral visual stream
What is anosagnosia?
inability to recognize deficits
Is astereognosia a problem with the primary or the secondary somatosensory cortex?
secondary
note: they have intact sensation but still cannot describe object in hand
pt must be able to physically manipulate objects to test this
Disorders of the dorsal visual stream cause what?
optic ataxia
-inability to use visual info to direct eye movement
The most common neglect disorder happens on the ______ side
left, because R parietal cortex dominates attention
What cortex dominates control of attention
right parietal cortex
True or false: damage to primary motor cortex can cause dysarthria
true
also weakness and loss of fractionated limb movement
Broca’s area is inside of what gyrus
inferior frontal gyrus
damage to the supplementary motor cortex
acutely a person will show _______________
hemiparesis/hemiplegia
(only acutely/right after)
damage to the premotor cortex leads to what?
Problems w/
speed/automaticity of reaching grasping
movement sequencing
posture and gait
Uncontrolled repetitive movements are called what?
Perseveration
note: due to damage of motor planning areas
ideational apraxia is…
inability to use objects appropriately especially when sequencing is necessary
Can’t use tools or spoon
ideomotor apraxia is what?
inability to develop movement sequence especially to a command
note: they can still do it instinctively/automatically when not thinking about it
What is magnetic gait?
Person has extreme difficulty lifting foot from floor to initiate gait
What are the 4 As of cerebral cortex disorders
Aphasia
Apraxia
Agnosia
Asterognosis
What are functional neurologic disorders
-used to be called conversion/psychogenic disorder
No structural or organic damage!
-not a psychiatric or psychological disorder
genuine motor and sensory dysfunction unexplained by medicine
worse or different symptoms than expected from testing
Complex regional pain syndrome and persistent perceptual postural dizziness are examples of…
functional sensory disorders
If a person has absent proprioception during testing but is able to do a finger to nose task with eyes closed or tandem walk, they might have…
functional sensory disorder
Functional movement disorders have test findings that are….
not consistent with preformance
What is a hoover sign?
indicative of functional movement disorder
Weak hip extension initially but then with contralateral hip flexion, the hip extensors will activate strongly
What is whack-a-mole sign
indicative of functional movement disorder
tremor moves to another body part when you restrain it
What is give-way weakness?
indicative of functional movement disorder
strong but then abrupt collapse without pain (when resisting MMT i guess)
