Cerebral Hemispheres

Question 1

Processing, interpretation, storage, retrieval, and neuronal patterning of language are neuronal intensive activities. Language is not only encephalized; it is also lateralized. What allowed this lateralization?

Answer 1

The development of the corpus callosum allowed lateralization of a specific function to reside in one hemisphere yet still share its information with the other side

Question 2

What are the Brodmann area numbers for the sensory cortices and language areas:
Primary somesthetic
Primary auditory
Primary visual
Broca's speech area
Wernicke's area

Answer 2

1-3
41-42
17
44-45
22

Question 3

What are the Brodmann area numbers for 
Occipital eye field
Frontal eye field
Primary motor
Premotor area

Answer 3

17
8
4
6, 8

Question 4

Describe layers I-II of the cerebral cortex

Answer 4

Form the most superficial layers of cortex
Play important roles in association and higher cognitive functions such as memory, interpretation of sensory input, and certain discriminative functions

Question 5

Describe layers III-IV of cerebral cortex

Answer 5

Receive most of the afferents into cortex

However, only 1% are thalamocortical fibers. Rest are corticocoritcal fibers

Question 6

Describe layer V-VI of the cerebral cortex

Answer 6

Innermost layers of cortex

Source of efferents from cortex such as association fibers, commissural fibers, and projection fibers

Question 7

Describe superior longitudinal fasciculus (SLF) or arcuate fasciculus

Answer 7

Interconnects frontal, parietal, and occiptal lobes

Critical link for language association areas

Question 8

What do lesions of SLF or arcuate fasciculus result in?

Answer 8

Conduction aphasia
Patients are fluent with only minor word finding pauses and paraphasia, their ability to repeat words or sentences is severely impaired
Comprehension and reading ability is intact, but writing shows error in spelling, word selection, and syntax

Question 9

What does the cingulum do?

Answer 9

Interconnects septal area, cingulate, and parahippocampal gyri to entorhianl cortex

Question 10

What does the uncinate fasciculus do?

Answer 10

Interconnects base of association areas of frontal lobe to inferior temporal lobe
Connected to entorhinal cortex

Question 11

What fibers are in the genu of the internal capsule? What does a lesion result in?

Answer 11

Corticobulbar fibers

Supranuclear facial palsy

Question 12

What are fibers in the posterior limb of the internal capsule? What do lesions result in?

Answer 12

Corticospinal fibers -> contralateral spastaic hemiplegia
Somesthetic fibers (thalamocortical) -> contralateral hemianesthesia

Question 13

What fibers are in the retrolenticular region of the internal capsule? What do lesions result in?

Answer 13

Optic radiations

Contralateral homonymous hemianopia

Question 14

What does an occlusion of the middle cerebral artery result in?

Answer 14

Sensory of motor deficits in contralateral upper limb and head

Question 15

Describe the process of encephalization of sensory and motor systems

Answer 15

Sophisticated sensory and motor systems have become dependent upon development of cortical areas, which could discriminate, analyze, interpret, and respond to specific stimuli
This upward shifting of functions to the cortex is encephalization