Thalamus & Cerebral Cortex

Question 0

cerebral cortex’s largest source of afferent fibers is from

Answer 0

the thalamus

Question 1

cerebral cortex contains how many neurons?

Answer 1

15 billion

Question 2

cerebral cortex inputs

Answer 2

brainstem reticular formation (MAO inputs)
basal forebrain (basal ganglia and limbic system)
association fibers within cx
contralateral cx

Question 3

cerebral cortex generates activity forming the basis of…

Answer 3

voluntary movement
sensory perception
learning
memory
language
emotions

Question 4

cells in cerebral cortex are arranged

Answer 4

in narrow bands arranged vertically

Question 5

6 layers of cells in the cerebral cortex

Answer 5

I - molecular (interneurons)
II - granule (inputs)
III - pyramidal (outputs)
IV - granule (inputs)
V - pyramidal (outputs)
VI - multiform

Question 6

primary sensory cells

Answer 6

layers II and IV

Question 7

primary motor cells

Answer 7

layers III and V

Question 8

some afferents from the cx are slower and are mediated by

Answer 8

ACh, MAO’s, and peptides

Question 9

pyramidal cells can

Answer 9

integrate wide variety of inputs
send signals to other layers within columns and other parts of the cortex or beyond the cx
may excite neurons in same column, inhibit adjacent columns

Question 10

columns arranged

Answer 10

in alternating fashion

this allows distinctive sensory or motor elements related to the same body part to be adjacent

Question 11

M1 Broadman’s area

Answer 11

4

Question 12

SMA & PMC Broadman’s area

Answer 12

6

Question 13

S2 Broadman’s area

Answer 13

5, 7

Question 14

V1 Broadman’s area

Answer 14

17

Question 15

V2 Broadman’s area

Answer 15

18

Question 16

V3 Broadman’s area

Answer 16

19

Question 17

A1 Broadman’s area

Answer 17

41

Question 18

A2 Broadman’s area

Answer 18

42

Question 19

4 general function categories of cx

Answer 19

1 - primary sensory areas
2 - primary motor areas
3 - unimodal association cortex (adjacent to each primary sensory area, higher level of info processing, perception of the sensation)
4 - multimodal association cortex

Question 20

multimodal association cortex includes

Answer 20

parieto-occipital-temporal junction
prefrontal area
limbic area

Question 21

parieto-occipital-temporal junction

Answer 21

spatial orientation, comprehension, visual processing of words

Question 22

prefrontal area

Answer 22

planning of complex patterns of behavior
sequence & elaboration of thought
expression of emotion

Question 23

limbic area

Answer 23

affective behaviors
autonomic behaviors
memory

Question 24

parietal association cortex

Answer 24

altering how we focus our attention spatial relationships attention

Question 25

(multimodal) parietal association cortex

Answer 25

concentrated in the parietal association cortex of the non-dominant hemisphere

Question 26

parietal association area is

Answer 26

the most highly lateralized area in the brain

Question 27

lesion in the non-dominant parietal association cortex

Answer 27

defect of attention contralateral neglect lack of spatial orientation

Question 28

contralateral neglect

Answer 28

patient seems unaware of objects & events in the contralateral half of their body or surrounding space

Question 29

lack of spatial orientation

Answer 29

inability to function within spatial surroundings | inability to describe route or relation between things (ex: bed and the chair next to it)

Question 30

apraxia

Answer 30

disorder of motor control/voluntary skilled learned movement deficit in motor planning inability to initiate & perform purposive movements

Question 31

apraxia common in brain lesions

Answer 31

that involve dominant hemisphere | that involve - parietal association cortex, premotor cortex, supplementary cortex

Question 32

types of apraxia

Answer 32

ideational ideomotor constructional

Question 33

ideational apraxia

Answer 33

most severe Purposeful movement is NOT possible automatically or on command Inability to understand the concept of the movement Inability to describe movement

Question 34

ideomotor apraxia

Answer 34

Purposeful movement may be performed automatically but is NOT possible on command Patient able to do habitual tasks & describe them but NOT able to initiate it or perform it on command Disconnection between the idea of the movement & motor execution

Question 35

constructional apraxia

Answer 35

Inability to internalize & duplicate spatial relationships among objects Inability to duplicate simple block construction while looking at model even though NO visual or fine motor defects Inability to remember locations of a group of objects

Question 36

Agnosia

Answer 36

inability to know something

Question 37

agnosia manifests as

Answer 37

inability to understand how sensory cues translate into meaningful concepts, though patient retains basic sensory abilities

Question 38

agnosia results from

Answer 38

damage to modality-specific sensory association areas

Question 39

types of agnosia

Answer 39

``` visual auditory tactile color olfactory ```

Question 40

visual agnosia

Answer 40

not able to recognize object seen visually but will recognize it thru sound, touch, or smell

Question 41

prefrontal area

Answer 41

``` Abstract intellectual abilities: judgement foresight sense of purpose responsibility social propriety ``` last area of cortex to mature

Question 42

lesion in prefrontal cortex affects

Answer 42

-intellectual abilities, personality, character Become: -highly distractible -lack of foresight -unusually stubborn -lack of ambition & sense of responsibility

Question 43

highly distractible

Answer 43

lack of consistency of purpose

Question 44

lack of foresight

Answer 44

ability to anticipate or predict future

Question 45

unusually stubborn

Answer 45

in face of advice that they do not agree

Question 46

dominant vs non-dominant hemisphere

Answer 46

language controlled by dominant (left for most people) | right for various spatial relations skills

Question 47

corpus callosum

Answer 47

where info from one side of the brain transferred to other | sent from layers II & III to more superficial layers

Question 48

cross-cortical connections in M1

Answer 48

fewer connections for distal muscles more for axial muscles (these function relatively independently)

Question 49

expressive speech area

Answer 49

Broca's area | 44, 45

Question 50

receptive language area

Answer 50

Wernicke's area | 22 (37, 39, 40)

Question 51

types of aphasia

Answer 51

expressive - Broca's aphasia receptive - Wernicke's aphasia conductive global

Question 52

Broca's aphasia

Answer 52

expressive/non fluent aphasia | occurs with lesions of frontal branches of MCA or by a tumor

Question 53

Broca's aphasia severe cases

Answer 53

unable to speak

Question 54

Broca's aphasia less severe cases

Answer 54

- slow difficult articulation - limited vocabulary - simple words or expressions - inappropriate words used (under stress or frustration) - difficulty writing - may have motor symptoms on lower face and arm

Question 55

agraphia

Answer 55

unable to write

Question 56

Wernicke's aphasia

Answer 56

receptive or fluent aphasia comprehension problem often caused by lesions of temporal & parietal branches of MCA or by hemorrhage into thalamus

Question 57

Wernicke's aphasia presents as

Answer 57

- speech sounds fluent but content is confused - may exhibit 'word salad' - nonsensical combo of words - may be unable to read & write - may NOT be aware of disability

Question 58

alexia

Answer 58

inability to read

Question 59

conductive aphasia

Answer 59

interruption in link b/w Wernicke's and Broca's areas spontaneous expression fluent comprehension is normal inability to translate what was heard into an appropriate reply

Question 60

global aphasia

Answer 60

profound disorder with complete loss of language | lesion in left internal carotid or the most proximal part MCA

Question 61

language and right hemisphere

Answer 61

other aspects of language (prosody of speech)

Question 62

there are different pathways for repeating words that are...

Answer 62

heard or read

Question 63

3 groups in thalamus

Answer 63

lateral anterior medial

Question 64

lateral nuclei transmit

Answer 64

somatosensory, visual, auditory, and taste info into posterior cortex and other regions

Question 65

anterior nuclei connect to

Answer 65

hippocampus cingulate gyrus mammillary bodies

Question 66

medial nuclei project

Answer 66

widely throughout cx - 'non-specific nuclei'

Question 67

thalamic nuclei can be categorized as

Answer 67

specific association non-specific

Question 68

specific thalamic nuclei

Answer 68

``` VPM VPL MG LG input from sensory pathways project topographically to specific regins of cx especially to pimary sensory areas ```

Question 69

association thalamic nuclei

Answer 69

``` VA VL Pulvinar Anterior input from basal ganglia, cerebellum, non-specific thalamic nuclei projec to specific regions cx ``` complex cognitive & integrative functions

Question 70

non-specific thalamic nuclei

Answer 70

mediodorsal centromedian projec to wide regions of cx NOT topographically organized modulate activity across broad regions of cx input from MAO axons & reticular formation

Question 71

most cortical regions...

Answer 71

receive multiple thalamic inputs & have reciprocal relationships with thalamic nuclei