Raj - thalamus, cerebral cortex

Question 1

forebrain (prosencephalon)

Answer 1

contain diencephalon and cerebral hemisphere

Question 2

thalamus

Answer 2

gateway to cerebral cortex

-nerve fibers run within internal medullary lamina

Question 3

nuclei of thalamus - lateral nuclear group specifics

Answer 3

• ventral posteromedial, posterolateral –> somatosensory cortex
• ventral lateral –> primary motor
• ventral anterior –> premotor and supplementary motor cortex

Question 4

thalamic lesions

Answer 4

1. vascular accidents = posterior cerebral and posterior communicating arteries
2. strokes, tumors –> loss of sensation on contralateral side; mimic cortical defects

Question 5

lateral vs. medial geniculate nucleus

Answer 5

lateral - visual

medial - auditory

Question 6

nuclei of thalamus - lateral nuclear group nonspecifics

Answer 6

1. lateral dorsal –> cingulate gyrus; limbic system
2. lateral posterior –> sensory association cortex in parietal lobe
3. pulvinar (largest) –> parieto-occipital-temporal association cortex

Question 7

anterior nuclear group

Answer 7

anteroventral, -medial, -dorsal

-project to cingulate cortex –> limbic system

Question 8

medial nuclear group

Answer 8

mediodorsal nucleus –> efferents to prefrontal cortex (mood and emotions)

Question 9

reticular nucleus

Answer 9

only nuclei sending efferent to thalamus and not cortical areas
-inhibitory (GABA) efferents

Question 10

neocortex

Answer 10

6 layers

• layer 4 –> termination of afferent fibers of thalamic nuclei
• layer 5 –> origin of extracortical targets; in primary motor cortex; contain Betz cells

Question 11

central sulcus

Answer 11

• behind –> post central gyrus (primary somatosensory cortex)
• in front –> pre central gyrus (primary motor cortex)
• separates frontal from parietal lobe

Question 12

brodmanns areas

Answer 12

• somatosensory –> area 1, 2, 3
• primary motor –> area 4
• premotor –> area 6
• frontal eye field –> area 8
• brocas area –> 44, 45
• primary auditory –> area 41, 42
• primary visual –> area 17

Question 13

motor cortexes

Answer 13

• premotor cortex - less focused
• supplementary motor - role in posture
• both help primary motor cortex

Question 14

frontal eye field

Answer 14

control conjugate eye movements

• area 8
• unilateral damage –> conjugate deviation of eyes towards side of lesion

Question 15

brocas area

Answer 15

motor speech area in dominant hemisphere

-language function - connections to temporal, parietal, occipital

Question 16

left frontal lobe lesions

Answer 16

• partial seizures - contralateral jerking movements (Jacksonian seizures)
• sensory/motor deficit - weak face and UMN on opposite side (contralateral hemiplegia)
• psychological deficit - trouble speaking, good comprehension (broca’s aphasia)

Question 17

bilateral cortical disorders

Answer 17

1. Alzheimer’s disease = degenerative
   - atrophy of temporal, parietal, and limbic system
   - aphasia (lose language) and amnesia (lose memory)
2. General paralysis of insane = neurosyphilitic infection
   - destroy both frontal lobes
   - alter personality, judgement, planning, behavior

Question 18

association cortex of parietal lobe

Answer 18

1. superior parietal lobule - interpretation of sensory info. and awareness of contralateral half of body
2. inferior parietal lobule - interface b/w somatosensory, visual, and auditory (language in dominant hemisphere)
   - damage –> visual and auditory problems

Question 19

parietal lobe lesions

Answer 19

1. left parietal lobe lesion
   - partial seizures
   - sensory/motor deficit - lose inferior visual field
   - psychological deficit - cannot name (anomia), read (Alexia), write (agraphia), or calculate (acalculia)
2. right parietal lobe lesion
   - same as above
   - psychological deficit - inability to copy and construct designs bc of spatial disorientation (constructional apraxia)

Question 20

auditory association cortex

Answer 20

known as wernickes area in dominant hemisphere

-understanding/comprehending language

Question 21

left temporal lobe lesions

Answer 21

• partial seizures - unresponsiveness (absences), behavior (automatism), olfactory visual and auditory hallucinations, memory and mood disturbance (de ja vu)
• contralateral superior visual field affected
• fluid speech, word errors (paraphasia), incomprehensible (wernicke’s aphasia)

Question 22

occipital lobe lesions

Answer 22

• visual hallucinations
• contralateral visual field loss (contralateral homonymous hemianopia)
• bilateral lesion –> cortical blindness (Anton’s syndrome)
• prevent recognition (apperceptive visual agnosia)