37 Cerebral hemisphere 1

Question 1

__________ separates the frontal and parietal lobes.

Answer 1

Central sulcus

Question 2

Name the main cortices in the frontal cortex from anterior to posterior.

Answer 2

1. prefrontal association cortex
2. premotor cortex
3. primary motor cortex

Question 3

Name the main cortices in the parietal lobe from anterior to posterior.

Answer 3

1. primary somatosensory cortex

2. posterior parietal cortex

Question 4

Name important structures in the occipital lobe.

Answer 4

Primary visual cortex, associated visual areas

Question 5

Name the important structures in the temporal lobe.

Answer 5

Primary auditory areas, associated auditory areas

Question 6

List 3 association cortices.

What is the main function of association cortices?

Answer 6

1. Limbic cortex
2. Parietal-temporal-occipital cortex
3. Prefrontal cortex

• store old information, process new and old information to make a new decision

Question 7

Afferents and efferents of prefrontal cortex?

Answer 7

Afferents:

1. parietal-temporal-occipital cortex
2. high-order sensory cortex

Efferents

1. parietal-temporal-occipital cortex
2. premotor cortex

Question 8

Name the 6 layers of the cortex covered by pia mater.

Answer 8

Layer 1-3: association/ commissural layers
Layer 4: afferent layer
Layer 5-6: efferent layers

Question 9

What is the afferents of layer 4 sensory cortex?

Answer 9

inputs from ventral posterior thalamic neuron

Question 10

What is the flow of information from layer 4 ?

Answer 10

Layer 4 > synapse with stellate cells > layers 2 and 3 > layer 1 + some associated fibers (AF)

Question 11

In sensory cortex, layer __ is/are very thick.

In motor cortex, layer ____is/are very thick.

Answer 11

4;

5 & 6

Question 12

Where is the thickest areas in the brain?

Answer 12

Limbic system in Temporal cortex

Question 13

Briefly describe the flow of vision from the retina to the primary visual cortex.

Answer 13

Nasal retina > contralateral lateral geniculate nucleus;
Temporal retina > Ipsilateral lateral geniculate nucleus
(thalamus)
> optic radiation > primary visual cortex

Question 14

Name the long association fibers tracts.

Answer 14

1. Superior longitudinal fasciculus
2. Inferior longitudinal fasciculus
3. Uncinate fasciculus

Question 15

Occipital cortex to frontal cortex is connected by the ____________, which is responsible for ______________ in our brain.

Answer 15

arcuate fasciculus;

language processing

Question 16

The anterior limb of IC is surrounded by?

Answer 16

lateral: GP + putamen
medial: head of caudate nucleus

Question 17

The posterior limb of IC is surrounded by ?

Answer 17

lateral: GP + putamen
medial: thalamus

Question 18

What fibers are present at the posterior limb of IC? Lesion of which artery is related?

Answer 18

Corticospinal fibers (+ corticopontine) at posterior limb;
middle cerebral artery (lateral striae: both anterior and posterior limb) +  anterior choroidal artery

Question 19

What fibers are present at the anterior limb of IC? Lesion of which artery is related?

Answer 19

Cortico-oculumotor fibers (+corticopontine)

supplied by medial striate artery from anterior cerebral artery

Question 20

What fibers are present at the genu of IC? Lesion of which artery is related?

Answer 20

Corticonuclei/ corticobulbar fibers;

supplied by middle cerebral artery; lesion > UMNL

Question 21

Area 4 is the?

Answer 21

Precentral gyrus, Primary motor area

Question 22

Afferents of area 4?

Answer 22

• somatosensory cortex,
• cerebellum,
• premotor cortex,
• supplementary motor area (corpus striatum)

Question 23

Efferents of area 4?

Answer 23

corticospinal tract (80%)
corticostriate pathway
corticobulbar tract (CN motor nuclei)
corticothalamic tract

Question 24

Face and hand have greater areas in the cortices because?

Answer 24

They are areas requiring larger number of muscles/ more neurons to produce muscle movements

Question 25

Area 6 is? | Where is its location?

Answer 25

Supplementary motor areas (medial surface) and premotor area (lateral surface) - anterior to area 4

Question 26

Function of supplementary motor area? | Lesion? (ipsilateral/bilateral)

Answer 26

Initiate movement ; Ipsilateral lesion: akinesia: difficulty in initiating movement; Bilateral lesion: total skinesia: total lack of initiation, muscle tone maintained

Question 27

Afferents and efferents of supplementary motor area?

Answer 27

Afferents: prefrontal cortex, basal ganglion (via VL), contralateral supplementary motor area Efferents: primary motor area, corticospinal tract

Question 28

Function of premotor area?

Answer 28

contain motor programmes, motor routines

Question 29

Afferents (under control of?) and efferents of premotor area?

Answer 29

Afferents: prefrontal cortex, basal ganglion (via VL), posterior parietal cortex (area 7, visual) Efferents: primary motor cortex, RF, corticospinal tract

Question 30

Area 8 is? Main function?

Answer 30

Frontal eye field (in front of premotor area); | voluntary saccadic eye movement towards opp hemi-visual field.

Question 31

Route of area 8.

Answer 31

FEF > PPRF (paramedian pontine reticular formation) > contralateral CN3 and ipsilateral CN6

Question 32

What is area 1,2,3a, b?

Answer 32

Primary somatosensory cortex

Question 33

What is area 5?

Answer 33

Somatosensory association cortex

Question 34

Posterior parietal cortex is area ____.

Answer 34

7

Question 35

What is stereognosis? Which brain parts are involved?

Answer 35

Ability to recognize 3D object with one's hand; dorsal column > relayes to VPLN > primary somatosensory cortex > somtatosensory association cortex > able to form picture of what u are holding

Question 36

Posterior parietal cortex is the ______________center in the brain to external stimuli. What is the neural route in searching objects of interest?

Answer 36

Attention; object at contralateral visual hemifield > activate cell columns in posterior parietal cortex > increase resting firing rate and cell columns in frontal eye field and premotor cortex > saccadic eye movements and reaching movements

Question 37

Hemineglect is caused by?

Answer 37

1. Lesion of posterior parietal cortex especially on the RIGHT > contralateral visual neglect, delayed and inaccurate saccades and reaching movements; 2. Lesion of the inferior parietal lobule > ignore opposite side of body unless attention is drawn to it

Question 38

Posterior parietal cortex is dominated in the ______ hemisphere.

Answer 38

right

Question 39

Inferior parietal lobule is area ______ and it is responsible for _______________.

Answer 39

40; | attention to internal environment

Question 40

Supramarginal gyrus is part of the?

Answer 40

Inferior parietal lobule

Question 41

_________________ contains a body schema, for awareness of existence and spatial relationships of body parts. Lesion of this area will cause?

Answer 41

Inferior parietal lobule (area 40); Lesion: hemineglect, ignore the opposite side of the body unless attention is drawn to it

Question 42

Right hemisphere is for ________________ in vision.

Answer 42

recognition of spatial relationships

Question 43

Left hemisphere is for ________________ in vision.

Answer 43

recognition of visual details

Question 44

Area 39 is? | Main function?

Answer 44

Angular gyrus; | initiates learned movements of some complexity

Question 45

Connections of the angular gyrus?

Answer 45

1. premotor area 2. prefrontal cortex 3. motor cortex

Question 46

Angular gyrus is dominant on the _______ side. Lesion will cause?

Answer 46

Left; | Ideomotor apraxia - failure to perform a learned movement on request.

Question 47

Angular gyrus is at the _________lobe, and it sends information to the premotor areas via _______________fasciculus.

Answer 47

parietal; | superior longitudinal