Cerebral Cortex II HY

Question 1

layers of the cortex

Answer 1

I: Molecular layer
II: External granule layer
III: External pyramidal layer
IV: Internal granule layer
V:  Internal pyramidal layer
VI: Polymorphic layer

granular = small
pyramidal = large

Question 2

agranular cortex is dominated by _________ cells

Answer 2

agranular cortex is dominated by LARGE PYRAMIDAL cells

Question 3

granular cortex is dominated by ________ cells

Answer 3

granular cortex is dominated by SMALL cells

Question 4

cortex functions

Answer 4

• integrates all sensory modalities
• plans/executes all motor activity, speech, and volitional action
• enables abstract thought, emotion, creativity
• controls attention :: modulates its own activity and focus

Question 5

thalamic sensory and relay nuclei —> what cortical layer?

Answer 5

layer IV (internal granule)

Question 6

input from intrathalamic nuclei —> what cortical layer?

Answer 6

layer VI (polymorphic)

Question 7

intracortical input —> what cortical input?

Answer 7

layers II/III (external granule/pyramidal)

Question 8

cortical layers that receive input

Answer 8

II/III: external granule/pyramidal
--intracortical input
IV: internal granule
---thalamic sensory/relay nuclei
VI: polymorphic
---thalamic nuclei

Question 9

cortical layers that have outputs

Answer 9

III: external pyramidal layer
---other cortical areas
V: internal pyramidal layer
---striatum, brainstem, spinal cord
VI: polymorphic
---thalamus

Question 10

cortical layer III has output to __________

Answer 10

cortical layer III has output to OTHER CORTICAL AREAS

Question 11

cortical layer V has output to __________

Answer 11

cortical layer V has output to STRIATUM, BRAINSTEM, SPINAL CORD

Question 12

cortical layer VI has output to __________

Answer 12

cortical layer VI has output to THALAMUS

Question 13

association fibers

Answer 13

intracortical white matter tracts

-stay within same hemisphere

Main:

• superior longitudinal fasciculus
• cingulum
• amygdalofugal pathway

Question 14

commissural fibers

Answer 14

intracortical white matter tracts

-project from 1 hemisphere to the other

Main:

• corpus callosum
• anterior commissure

Question 15

corpus callosum

Answer 15

• type of commissural fiber
• massive intracortical white matter tract
• contains 200-250 million axons

Question 16

anterior commissure

Answer 16

• type of commissural fiber
• connects the temporal lobes
• 1/10 size of corpus callosum

Question 17

superior longitudinal fasciculus

Answer 17

• a main association fiber
• connects frontal with posterior
• contains ARCUATE fasciculus: connects brain regions involved in generation/comprehension of language

Question 18

arcuate fasciculus

Answer 18

• within the superior longitudinal fasciculus (association fibers)
• connects brain regions involved in generation/comprehension of language

Question 19

cingulum

Answer 19

• a main association fiber
• forms nearly a complete circle
• from cingulate to parahippocampal gyrus

Question 20

amydalofugal pathway

Answer 20

• a main association fiber

- connects amygdala with thalamus, hypothalamus, basal forebrain, brain stem, septal nuclei, nucleus accumbens

Question 21

cortical columns are ______

Answer 21

cortical columns are MICROCIRCUITS

-many connections with other neurons in same column (and within columns)

Question 22

cortical columns process sensory input _________

Answer 22

cortical columns process sensory input TOPOGRAPHICALLY

-area of visual field corresponds to region in cortex

Question 23

direction-sensitive neurons

Answer 23

• type of functional organization
• some neurons only become active when light moves across the visual field in a certain direction
• due to the connections that each neuron makes with nearby neurons, and the excitatory/inhibitory nature of those connections

-converge with other neurons to integrate info into more complex things (recognize familiar faces/scenes/threats)

“columnar microcircuits work together to engender cellular behavior”

Question 24

fusiform gyrus

Answer 24

• activated during facial recognition

- higher order cortical center

Question 25

prosopagnosia

Answer 25

• “face blindness”

- disruption of circuits in fusiform gyrus

Question 26

what happens if you stimulate the fusiform gyrus with an electric current?

Answer 26

• prosopagnosia (face blindness)

- “face metamorphosed”