LOCALISATION OF CORTICAL FUNCTION Flashcards

1
Q

What are Cytoarchitectural studies?

A

: mapping out the functional areas of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the ways in which we can work out which regions control a particular function?

A
cytoarchitectural studies
post-mortem studies
intraoperative electrocortical stimulation
medical imaging
animal studies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is Intraoperative electrocortical stimulation?

A

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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the 2 arteries responsible for the blood supply to the brain?

A

internal carotid artery

vertebral arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe the path of the internal carotid artery?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe the path of the vertebral arteries?

A

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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the components of the circle of willis?

A

anterior cerebral arteries, internal carotid arteries, posterior cerebral arteries, anterior communicating artery and posterior communicating artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the anterior communicating artery?

A

the artery which connects the 2 anterior cerebral arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the posterior communicating artery?

A

the artery which connects the internal carotid artery to the posterior cerebral artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does the middle cerebral artery supply blood to?

A

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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the anterior cerebral artery supply blood to?

A

most midline portions of the frontal lobes and superior medial parietal lobes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does the posterior cerebral artery supply blood to?

A

medial and lateral parts of the posterior cerebrum including the occipital lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe the venous drainage system of the brain

A

dural venous sinuses drain the CNS, face and scalp. they ultimately drain into the internal jugular vein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what gives rise to the anterior, superior and inferior cerebellar arteries?

A

the basilar artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the pre-central gyrus?

what is its function?

A

primary motor cortex

for executing voluntary moveemnts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the post-central gyrus?

A

primary somatosensory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the motor homunculus?

A

a topographic representation of the body parts and its correspondents along the precentral gyrus of the frontal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the sensory homunculus?

A

a topographic representation of the body parts along the postcentral gyrus of the parietal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why do we need a motor and sensory homunculus?

A

as some parts of the body you can feel but can’t move e.g. scalp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

where is the supplementary motor cortex?

A

just anterior to the primary motor cortex (brodmanns region 6)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the function of the supplementary motor cortex?

A

contributes to the control of movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what happens if we get a lesion of the primary motor cortex?

A

contralateral flaccid paralysis which partially recovers

23
Q

what happens when we get a lesion of the supplementary motor cortex?

A

contralateral rigid paralysis and an increase in deep tendon reflexes

24
Q

which Brodmann region is the frontal eye field?

A

8 in frontal cortex

25
Q

what happens when you get a lesion in the frontal eye field?

A

difficulty moving eyes to opposite side

26
Q

which brodmanns region is the primary motor cortex?

A

4

27
Q

what brodmanns areas are the primary somatosensory cortex?

A

3,2 and 1

28
Q

what does a lesion in the primary somatosensory cortex cause?

A

decrease in contralateral touch, pressure and proprioception

29
Q

what is Brodmann’s area 40?

A

supramarginal gyrus

30
Q

what happens if we get a lesion at the supramarginal gyrus?

A

tactile and proprioceptive agnosia, loss of left-right discrimination, contralateral hemineglect and contralateral apraxia

31
Q

what is the function of Brodmann’s area 39?

A

language perception

32
Q

what would a lesion at Brodmann’s area 39 cause?

A

Alexia, dyslexia or agraphia

33
Q

what is hemispheric lateralisation?

A

the idea that the two halves of the brain are functionally different and that each hemisphere has functional specialisations

34
Q

how are the 2 hemispheres of the brain connected?

A

nerve fibres called the corpus callosum

35
Q

which is the dominant hemisphere?

A

the one in which language comprehension occurs (most often left)

36
Q

what functions are the left and right hemispheres usually dominant for?

A

the left hemisphere is dominant in terms of speech and language. the right hemisphere is dominant in terms of visual-motor tasks.

37
Q

what can lesions of the dominant hemisphere cause?

A

language dysfunction

38
Q

what is aphasia?

A

an inability to comprehend or formulate language because of damage to specific brain regions

39
Q

what is broca’s area?

A

a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production

40
Q

what is Wernicke’s area?

A

the region of the brain that is important for language development. It is located in the temporal lobe on the left side (usually) of the brain and is responsible for the comprehension of speech

41
Q

what would happen if you had a lesion in the Broca’s area?

A

you would know what to say but have difficulty expressing it, you would have slow laboured speech, you would delete prepositions, nouns and you would be non-fluent as the transitions would feel difficult.

42
Q

what would happen if you had a lesion in Wernicke’s area?

A

you would hear but wouldn’t be able to understand, you would have fluent effortless speech with lots of un-known mistakes, you would not be able to understand your own words and you would produce new words.

43
Q

how are Broca’s and wernickes areas connected?

A

a bundle of nerve fibers called the arcuate fasciculus.

44
Q

what is the Sylvian fissure?

A

separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly aka lateral sulcus

45
Q

where would we find the arcuate fasciculus?

A

around the Sylvian fissure

46
Q

what deficits would occur if we had a lesion in the middle cerebral artery?

A

contralateral upper limb weakness, partial blindness, global aphasia, contralateral hemineglect, decreased self awareness

47
Q

what deficits would occur if we had a lesion in the anterior cerebral artery?

A

contralateral lower limb weakness, contralateral sensory loss, frontal lobe behavioural abnormalities, contralateral hemineglect

48
Q

what deficits would occur if we had a lesion in the posterior cerebral artery?

A

contralateral partial blidness, contralateral hemisensory loss and hemiparesis (weakness on one side of the body)

49
Q

what is the neocortex?

A

the centre for higher brain functions e,.g. perception, decision-making, language

50
Q

what are the pre-frontal cortex’s functions?

A

abstract thinking, decision making, planning, prioritising, sequencing, adaptive and goal directed behaviour

51
Q

what would lesions in the pre-frontal cortex cause?

A

disinhibition. subtle personality changes, decreased concentration/judgement/abstract thought/foresight/tact/problem solving/initiative

52
Q

what is the Pareto-occipital sulcus?

A

it separates the parietal and occipital lobes

53
Q

what is the function of the calcimine sulcus?

A

primary visual cortex

54
Q

what is either side of the calcimine sulcus?

A

accessory visual cortexes