Cortex & Limbic System Flashcards
What’s associate and apperceptive agnosia?
They result from damage to which part of the brain?
Associative agnosia = see object but doesn’t recognise
Apperceptive agnosia = fail to perceive/see object
Damage to near tip of occipital lobe
Outline association interneurone connections with regards to sight
Primary visual cortex sees object
Medial occipital/temporal lobe recognises what it is
Detect its moving
Primary and pre-motor cortices move head to track it
Frontal eye field sees it
What’s prosopagnosia and achromatopsia?
Caused by damage to which part of the brain?
Prosopagnosia = inability to recognise faces
Achromatopsia = inability to recognise colour
Damage in fusiform gyrus (medial occipital/temporal lobe responsible for facial, shape and colour recognition)
Damage to which part of the brain leads to hemispatial neglect? How will you see this in a patient?
Posterior parietal cortex - superior lobule
Integrates sensory inputs and controls contralateral perception of body/environment
Patient will draw a clock face but only fill in half the numbers, or draw half of objects, make walk into things on affected side etc.
What’s the difference between Wernicke’s and Broca’s areas/aphasias?
Broca’s area concerned with motor component of speech - Broca’s aphasia will have correct content but may miss words/speak slowly/slurred
Wernicke’s area concerned with content of speech - Wernicke’s aphasia is receptive aphasia so fluent but content is incorrect
What cerebral artery supplied hearing, speech and language areas?
MCA
What’s a fasciculus?
A bundle of fibres sharing a similar function and route of travel
What does the arcuate fasciculus connect and what does damage there produce?
Broca’s area to Wernicke’s area = motor planning involved in speech to understanding heard/spoken/written word
Damage causes conductive aphasia = fluent dysphasic speech
Where does the anterior choroidal artery branch from and what does it supply?
Comes off ICA at circle of willis
Thalamus Choroid plexus Optic tract Lateral geniculate body - vision Posterior limb of internal capsule Limbic system
Where are the limbic system structures?
Immediately below the cortex - form a ring around the diencephalon (thalamus + hypothalamus) in temporal, frontal and parietal lobes
Rim of cortex (hippocampal and insula) and subcortical nuclei
What are the roles of the limbic system?
Sensation of emotions
Visceral responses to emotions
Memories
What’s the papez circuit?
Cingulate gyrus -> hippocampus -> fornix -> mamillary bodies of hypothalamus -> anterior thalamic nucleus -> cingulate gyrus
Where’s the hippocampus located and what’s its blood supply?
Inferomedial temporal lobe
PCA
What type of memory loss does damage to the hippocampus form?
Anterograde amnesia = unable to make new memories but can still recall old ones in LTM
What’s Korsakoff’s psychosis and the 3 main symptoms?
Metabolic damage/alcohol abuse -> thiamine B1 deficiency damaging mamillary bodies and thalamus
Anterograde amnesia (sometimes retrograde too)
Confabulation
Hallucinations
