Neuro-Cerebral Cortex

Front 1

What are the six layers of gray matter in the cerebral cortex?

Back 1

Layer 1-Molecular layer
Layer 2-External granular layer
Layer 3-External pyramidal layer
Layer 4-Internal granular layer
Layer 5-Internal pyramidal layer
Layer 6-Multiform layer

Front 2

What are the features of the molecular layer of gray matter?

Back 2

-Layer 1, most superficial
-Contains few cell bodies, but many fibers (axons and dendrites)

Front 3

What are the features of the external and internal granular layer of gray matter?

Back 3

-Layers 2 and 4
-Contain many small cells
-These layers are the receiving layers of the gray matter
-Thick in somatosensory area

Front 4

What are the features of the external pyramidal layer of gray matter?

Back 4

-Layer 3
-Contains medium-sized pyramidal cells
-Efferent layer, sends axons to other parts of the cerebral cortex (same side, contralateral side)

Front 5

What are the features of the internal pyramidal layer of gray matter?

Back 5

-Layer 5
-Contains medium-sized and large pyramidal cells
-Efferent layer, axons go to subcortical structures (basal ganglia, cerebellum, brainstem and spinal cord)

Front 6

What are the features of the mutiform layer of gray matter?

Back 6

-Layer 6
-Cells with spindle-shaped cell bodies
-Many efferent axons go to thalamus

Front 7

What is Brodmann's Area 4?

Back 7

MI (primary motor area)

Front 8

What is Brodmann's Area 3, 1, 2

Back 8

SI (primary somatosensory area)

Front 9

What is Brodmann's Area 6?

Back 9

Premotor area
Supplementary motor area

Front 10

What is Brodmann's Area 44, 45?

Back 10

Broca's area (expressive speech)

Front 11

What is Brodmann's Area 44?

Back 11

Pars Opercularis

Front 12

What is Brodmann's Area 45? Where is it found?

Back 12

Pars Triangularis; dominant hemisphere

Front 13

What is Brodmann's Area 22? Where is it found?

Back 13

Wernicke's area (receptive speech); dominant hemisphere

Front 14

What is Brodmanns' Area 41? Where is it located?

Back 14

Primary auditory area; superior temporal gyri (gyri of Heschl)

Front 15

What is Brodmann's Area 17? Where is it located?

Back 15

Primary visual cortex; occipital lobe

Front 16

What layers do most projection neurons come from?

Back 16

Layers 3 and 5, external and internal pyramidal layers

Front 17

Axons of neurons in layer 5 travel out of the cortex to where?

Back 17

-Brainstem
-Spinal cord
-Basal ganglia
-Cerebellum

Front 18

What are corticofugal fibers?

Back 18

Fibers passing outward from the cerebral cortex

Front 19

What are corticobulbar fibers?

Back 19

Fibers passing from cerebral cortex to brainstem nuclei

Front 20

What layer are most association fibers from?

Back 20

Layer 3

Front 21

Where do association fibers travel?

Back 21

To other parts of the cortex on the same side of the brain

Front 22

How long are association fibers?

Back 22

-May be short ('U' shaped arcuate fibers that connect adjacent areas)
-Long (connect distant areas and include named fiber tracts)

Front 23

What are two long association fibers?

Back 23

1. Uncinate fasciculus
2. Superior longitudinal fasciculus

Front 24

What two structures are connected by the uncinate fasciculus?

Back 24

The orbital gyri of frontal lobe and the temporal lobe

Front 25

Where do fibers from the superior longitudinal fasciculus run? Where do they enter and exit?

Back 25

From anterior frontal lobe to occipital and temporal lobes; enter and exit at various places, difficult to determine more precisely what parts of the cortex are connected

Front 26

Commissural fibers originate in what layer?

Back 26

Layer 3

Front 27

What do commissural fibers allow?

Back 27

-Allow information to be shared from one hemisphere to another
-Allow two hemispheres to cooperate during complex tasks
-Include the corpus callosum, anterior commissure, posterior commissure

Front 28

What are interneurons?

Back 28

Locally branching axons that do not project out of the gray matter

Front 29

What directions can interneurons travel in? Where do they mediate communication?

Back 29

-May travel vertically or horizontally
-Vertical projections mediate communication along a column of cells

Front 30

What parts of the cerebral cortex receive fibers from the thalamus?

Back 30

All parts

Front 31

Are thalamocortical fibers precisely arranged or more diffuse?

Back 31

-Most are precisely arranged (specific thalamic nuclei to specific part of cerebral cortex)
-Some thalamocortical projections more diffuse

Front 32

What are corticothalamic fibers?

Back 32

Reciprocal connections with thalamocortical fibers

Front 33

Where are the cell bodies of corticothalamic fibers located?

Back 33

In layer 6 of the cerebral cortex

Front 34

What is the function of corticothalamic fibers?

Back 34

They allow the cerebral cortex to influence the type and amount of signals that pass through the thalamus to the cortex from subcortical structures

Front 35

Association areas closes to primary cortical areas process how many types of information?

Back 35

One type of information (i.e. area 5 processes somatosensory info)

Front 36

Association areas farther from primary area process how many types of information?

Back 36

Multiple types (i.e. area 7 processes both visual and somatosensory info)

Front 37

A monkey has been trained to open a box without vision using its right hand. Will the monkey be able to open the box with its left hand if the right is restrained? What does this prove?

Back 37

Yes; proves that somatosensory information is shared with the other side of the brain

Front 38

A monkey has been trained to open a box without vision using its right hand? The monkey's commissural fibers have been transected. Will it be able to open a box with its left hand if the right hand is restrained?

Back 38

No

Front 39

What percentage of the human population is strongly left-hand dominant?

Back 39

2-3%

Front 40

What percentage of the general population (left and right dominant persons) have speech centers in the left hemisphere?

Back 40

95%

Front 41

What percentage of left-hand dominant persons have speech centers in the left hemisphere?

Back 41

70%

Front 42

What pathway is used to repeat a spoken word?

Back 42

Auditory cortex-Wernicke's area-Arcuate fasciculus-Broca's area-Motor cortex

Front 43

What pathway is used to repeat a written word?

Back 43

Primary visual cortex-Angular gyrus-Wernicke's area-Auditory cortex-Broca's area-Motor cortex