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Flashcards in Cerebral Cortex Deck (54):
1

What percentage of our cerebral cortex is neocortex?

>90%

2

What are the layers of the neocortex?

molecular layer
outer granular layer
outer pyramidal layer
inner granular layer
inner pyramidal layer
multiform layer

3

What is a homotypical cortex? What is it characteristic of?

displays all six layers equally
association cortex

4

What is a heterotypical cortex?

includes all six layers but some are more developed than others

5

What is heterotypical agranular cortex? What is it characteristic of?

outer and inner pyramidal layers expanded
granular layers less developed
motor cortex

6

What is heterotypical granular cortex? What is it characteristic of?

outer and inner granular layers expanded
pyramidal layers less developed
sensory cortex

7

Brodmann's area: Sensory: Primary cortex

1, 2, 3

8

Brodmann's area: Sensory: Higher order

5, 7

9

Brodmann's area: Visual: Primary

17

10

Brodmann's area: Visual: Higher order

18, 19

11

Brodmann's area: Auditory: Primary

41, 42

12

Brodmann's area: Auditory: Higher order

22

13

Brodmann's area: Association cortex

19, 21, 22, 37, 39, 40

14

Brodmann's area: Ideational speech area

21, 22, 37, 39, 40

15

Brodmann's area: Motor speech area

44, 45

16

Brodmann's area: Motor: Primary cortex

4

17

Brodmann's area: Motor: Premotor area

6

18

Brodmann's area: Motor: Frontal Eye Fields

8

19

Brodmann's area: Prefrontal cortex

9,10,11,12

20

What % of corticospinal and corticobulbar fibres originate from primary motor cortex? from premotor cortex? from parietal lobe?

30% primary motor
30% premotor
40% parietal

21

What is an apraxia?

inability to perform learned, skilled voluntary movements int eh absence of paralysis
may result from lesions affecting the premotor area

22

Which parts of the body are represented to a much larger proportion on the motor homunculus?

hand and face (areas require more control of fine motor movements)

23

What are projection fibres

fibres passing from one level of the CNS to a higher or lower level
eg internal capsule

24

What are commissural fibers

interconnect opposite sides of the brain
eg corpus callosum

25

What are association fibres

interconnects regions of the cerebral cortex within a hemisphere (eg cingulum of the limbic system)

26

What does the anterior limb of the internal capsule include?

reciprocal connections: anterior and dorsomedial thalamic nuclei, frontal & cingulate cortical areas
descending projections: from frontal lobe to pontine nuclei

27

What does the posterior limb of the internal capsule include?

reciprocal connections: ventral anterior, ventral posterior, VPM, VPL; cortex of frontal & parietal lobes

28

What pathway passes through the retrolenticular and sublenticular portions of the internal capsule?

visual pathway connecting lateral geniculate body with visual cortex (occipital lobe)

29

What pathway passes through the sublenticular portions of the internal capsule only?

Auditory pathway connecting medial geniculate body with temporal lobe

30

It is thought that the external and extreme capsule contain what types of fibres

association fibres
external: projection fibres from cortex to putamen

31

The claustrum is reciprocally connected to the

cerebral cortex

32

The lateral ventricles are associated with what region of the brain

telencephalon

33

The anterior horn of the lateral ventricles extend into what lobes

frontal lobes

34

The posterior horn of the lateral ventricles extend into what lobes

occipital lobes

35

The inferior horn of the lateral ventricles extend into what lobes

temporal lobe

36

What is the trigone of the lateral ventricles?

The region where the anterior horn, posterior horn and inferior horn come together.

37

What cavity is associated with the diencephalon?

third ventricle

38

The third ventricle is continuous with the lateral ventricle through what

interventricular foramen

39

The third ventricle is continuous with the fourth ventricle through what

cerebral aqueduct

40

What cavity is associated with the pons and medulla?

fourth ventricle

41

The fourth ventricle opens into the __ via the ____

subarachnoid space via the two lateral foramina of Luschka and the medial foramen of Magendi

42

What is a homotypical cortex? Where is it found?

Cortex where all six layers of the neocortex are more or less the same.
Association areas

43

What cell types are found in molecular layer?

few neurons
mainly incoming axons and dendrites of more deeply placed cells

44

What cell types are found in external granular layer?

pyramidal & granular (stellate) cells

45

What cell types are found in external pyramidal layer?

pyramidal cells

46

What cell types are found in internal granular layer

granule (stellate) cells

47

What cell types are found in multifom layer?

fusiform & pyramidal cells

48

What is granular heterotypical cortex? Where is this found?

layers II & IV expands
primary visual, auditory and somatosensory cortices

49

What are the layers of the neocortex from I-VI?

I molecular
II - external granular
III - external pyramidal
IV - internal granular
V - internal pyramidal
VI - multiform

50

What is agranular heterotypical cortex? Where is this found?

layers III and V predominate
primary motor cortex

51

In the heterotypical granular cortex, both internal and external granular layers are thickened. Why the internal more than the external?

sensory thalamic nuclei terminate preferentially in layer IV (internal granular layer)

52

Why is the primary visual cortex also called the striate cortex?

stria Gennari enters visual cortex from lateral geniculate body of thalamus

53

Primary motor cortex can be recognized by the presence of what types of cells int he internal pyramidal layer?

cells of Betz

54

Why are the external and internal pyramidal layers of the primary motor cortex so well developed?

primary motor cortex is the source of large numbers of projection fibers which originate from the pyramidal cell layers and extend to motor nuclei in brainstem and spinal cord