Localisation of cortical function Flashcards
What does the grey matter contain?
Collection of cell bodies and nuclei. The grey matter of the cerebrum is the cortex.
What does the white matter contain?
Bundles of axons which form tracts in the CNS.
What are the derivatives of the lateral ventricles?
Telencephalon
What is the derivative of the 3rd ventricle?
Diencephalon
What are the derivatives of the cerebral aqueduct?
Mesencephalon
What are the derivatives of the superior 4th ventricle?
Metencephalon
What is the derivative of the inferior 4th ventricle?
Myencephalon
What are the flexures of the embryo?
There are 3 flexures: cephalic flexure which seperates the prosencephalon from the mesencephalon
Pontine flexure which seperates the metencephalon and myencephalon
Cervical flexure which separates the brain from the spinal cord
What is dorsal in the brain?
Superior and in the brainstem Posterior
What is ventral in the brain?
Inferior and in the brainstem anterior
What is the folia?
Depressions in the cerebellum/gyri of the cerebellum
What is the cingulate gyrus?
Superior to the corpus callosum and part of the limbic system for behavioural and emotional control
What is the calcarine sulcus?
Opening into the occipital lobe for vision.
What is the uncus?
Part of the temporal lobe
What is the venous drainage in the brain?
Via the 6 dural venous seinuses. the superior and inferior petrosal veins, the superior and inferior saggital, transverse vein,, occipital vein and straight vein.
These drain into the sigmoid vein-> internal jugular vein -> subclavian vein -> heart
What are the differences in sensory and motor somatotropic map?
Sensory- hands, genitals, toes and feet, mouth and tongue and head
Motor- hands, head, tongue
What is Brodmann’s areas 4 and 6?
Area 4: primary motor cortex for initiating movement. Lesion leads to contralateral flaccid paralysis and Babinski sign
Area 6: pre-motor cortex for co-ordinating movement to somatotropic map. Lesion leads to contralateral spasticity and increased deep tendon reflexes
Area 8: supplementary cortex to interpret signals for movement. Lesions lead to issues with ocular movement.
What is agnosia?
Inability for recognition of propioception (self limbs) or objects.
What does a lesion in Brodmann’s areas 1-3, 39-40 cause?
Area 1-3: contralateral hemineglect, sensory loss
Area 2: contralateral loss of pain
Area 39: contralateral dyslexia, alexia and agraphia
Area 40: contralateral loss of left and right awareness
What are the commisual fibres?
Allows the communication between the left and right hemisphere.
What is hemispheric specialisation?
Anatomical symmetry between the left and right hemisphere however there is difference in sensory input and motor function
What is apraxia?
Loss of fine and skilled movement
What is hemispheric dominance?
Either of the right or left hemispheres assumes primary control of language, apraxia and direction.
What is the role of the non-dominant hemisphere?
The non-dominant hemisphere is resonsible for adding emotion to speech, estimation for maths and visual awareness for direction.
What is the role of the dominant hemisphere?
Dominant hemisphere is responsible for language, speech, calculation and sense of direction.
What is the role of the non-dominant hemisphere?
The non-dominant hemisphere is resonsible for adding emotion to speech, estimation for maths and visual awareness for direction.
What does a lesion in the dominant hemisphere cause?
Language difficulties- in children, the contralateral hemisphere will assume control eventually.
What is sensory aphasia?
Receive sensory input such as hearing but cannot interpret or understand it- motor functions are normal.
What is motor aphasia?
Slow, laboured speech and diffculty with apraxia such as writing.
What is the source of hearing in the brain?
Bilateral cortical areas in the brain, innervated by cranial nerve 8
Where is the source of the lesion with hearing loss?
Cranial nerve 8
What is the primary blood supply to the brain?
Middle cerebral artery supplies 60-80% of total blood supply and is found in the lateral sulcus within the insula grey matter. It supplies blood ofor speech, face and eye movement
What is the stroke artery?
Middle cerebral artery
What is the role of the pre-frontal cortex?
Higher level functioning such as abstract thought, inhibition, personality, judgement and planning
What is the consequence of a lesion in the pre-frontal cortex?
Loss of inhibition, impulsiveness, changes in personality, difficulty in judgement
What does the anterior cerebral artery?
Anterior cerebral artery supplies the medial surface of the cerebral cortex to the parietal-occipital sulcus. It has a medial striate branch which supplies the deeper structures of the brain.
What is the pericallosal artery?
Branch of the anterior cerebral artery which supplies the corpus callosum.
What is the Medial striate artery of Heubner?
Branch of the anterior cerebral artery which supplies the deeper structures of the brain such as the internal capsule.
What is hemianopia?
Loss of vision in one side.
What is agnosia?
Loss of object recognition.
What is posterior cerebral artery?
Supplies the areas of the brain for vision in the cortex- loss of supply to this can lead to contralateral heminopia.
