Fiber stuff

Question 1

what are the commissural fibers?

Answer 1

connects the two hemispheres

Question 2

what makes up the commissural fibers?

Answer 2

corpus callosum

anterior commissure

posterior commissure

fornix

Question 3

what are the association fibers?

Answer 3

connections in the same hemisphere

Question 4

association fibers will divide into what 2 types?

Also, what will they connect?

Answer 4

1) short: connects adjacent gyri (arcuate fibers)
2) long: connects different lobes

Question 5

what are the major associations fibers? what will each connect?

Answer 5

1. superior longitudinal fasciculus: connects frontal, parietal, occipital lobes
2. arcuate fasciculus: connects the temporal lobe, also Wernicke’s and Broca’s
3. Cingulum: connects cingulate gyrus to other limbic structures

Question 6

what are projection fibers?

what is another name for these?

Answer 6

fibers that ascend or descend to brainstem or spinal cord

also called subcortical

Question 7

what are the 2 types of projection fibers? in which direction do they go?

which is sensory and motor?

Answer 7

1. coriticopetal: towards the cortex
   * sensory
2. corticofugal: from the cortex
   * motor

Question 8

what are the 4 examples of corticofugal (type of projection fiber) fibers?

which ones are the only that go anterior?

which one goes posterior?

Answer 8

1) Corticospinal to spinal nerves
2) Corticobulbar/nuclear to cranial nerves
3) Corticostriate and Corticopontine
4) extrapyramidal tracts (corticorubral)

Corticostriate and cortipontine; corticospinal and corticobulbar go through the anterior limb

extrapyramidal tracts go through the posterior limb

Question 9

what type of neurons use the coriticopedal type of projection fibers?

Answer 9

3rd order neurons from the VPL and VPM that are going to the cortex

on their way they go through the posterior limb

Question 10

what are the parts of the corpus callosum?

Answer 10

Question 11

which fiber connects Broca’s to Wernicke’s?

Answer 11

arcuate fasciculus