LOCALISATION OF CORTICAL FUNCTION Flashcards
What are Cytoarchitectural studies?
: mapping out the functional areas of the brain
what are the ways in which we can work out which regions control a particular function?
cytoarchitectural studies post-mortem studies intraoperative electrocortical stimulation medical imaging animal studies
what is Intraoperative electrocortical stimulation?
awake brain surgery, stimulate an area of the brain with electrodes and ask the patient the effect of this, this is also useful to ensure during brain surgery there is no damage to functional areas. Forms topographic maps.
what are the 2 arteries responsible for the blood supply to the brain?
internal carotid artery
vertebral arteries
describe the path of the internal carotid artery?
arteries originate at the bifurcation of the left and right common carotid arteries
They move superiorly within the carotid sheath, and enter the brain via the carotid canal of the temporal bone.
Once in the cranial cavity, the internal carotids pass anteriorly through the cavernous sinus.
The internal carotids then continue as the middle and anterior cerebral artery
describe the path of the vertebral arteries?
The right and left vertebral arteries arise from the subclavian arteries, medial to the anterior scalene muscle. They then ascend the posterior aspect of the neck, through foramen transversarium (holes in cervical vertebrae).
The vertebral arteries enter the cranial cavity via the foramen magnum.
The two vertebral arteries converge to form the basilar artery.
The basilar artery terminates by bifurcating into the posterior cerebral arteries.
what are the components of the circle of willis?
anterior cerebral arteries, internal carotid arteries, posterior cerebral arteries, anterior communicating artery and posterior communicating artery.
what is the anterior communicating artery?
the artery which connects the 2 anterior cerebral arteries
what is the posterior communicating artery?
the artery which connects the internal carotid artery to the posterior cerebral artery
what does the middle cerebral artery supply blood to?
portion of the frontal lobe and the lateral surface of the temporal and parietal lobes, including the primary motor and sensory areas of the face, throat, hand and arm, and in the dominant hemisphere, the areas for speech.
what does the anterior cerebral artery supply blood to?
most midline portions of the frontal lobes and superior medial parietal lobes.
what does the posterior cerebral artery supply blood to?
medial and lateral parts of the posterior cerebrum including the occipital lobe
describe the venous drainage system of the brain
dural venous sinuses drain the CNS, face and scalp. they ultimately drain into the internal jugular vein.
what gives rise to the anterior, superior and inferior cerebellar arteries?
the basilar artery
what is the pre-central gyrus?
what is its function?
primary motor cortex
for executing voluntary moveemnts
what is the post-central gyrus?
primary somatosensory cortex
what is the motor homunculus?
a topographic representation of the body parts and its correspondents along the precentral gyrus of the frontal lobe
what is the sensory homunculus?
a topographic representation of the body parts along the postcentral gyrus of the parietal lobe
why do we need a motor and sensory homunculus?
as some parts of the body you can feel but can’t move e.g. scalp
where is the supplementary motor cortex?
just anterior to the primary motor cortex (brodmanns region 6)
what is the function of the supplementary motor cortex?
contributes to the control of movement
what happens if we get a lesion of the primary motor cortex?
contralateral flaccid paralysis which partially recovers
what happens when we get a lesion of the supplementary motor cortex?
contralateral rigid paralysis and an increase in deep tendon reflexes
which Brodmann region is the frontal eye field?
8 in frontal cortex
