White matter pathways

Question 1

Projection fibers

Answer 1

Run vertically connecting higher and lower centers of the brain

Question 2

Association fibers

Answer 2

Interconnect different regions within the same hemisphere of the brain

Question 3

Commissural fibers

Answer 3

Interconnect similar regions in the opposite hemisphere

Question 4

Corpus callosum

Answer 4

Largest bundle of fibres that connect the two cerebral hemispheres
Anterior supplied by the pericallosal artery (derived from the anterior cerebral artery)
-left sided apraxia and agnosia may be seen in cases of vascular disruption
-posterior cerebral artery supplies the posterior of teh corpus callosum (splenium). Disruption causes alexia and colour anomia but preserved ability to copy words

Question 5

Anterior commissure

Answer 5

Interconnects olfactory bulbs

Question 6

Posterior commissure

Answer 6

Interconnects midbrain pretectal nuclei

Question 7

Hippocampal commissure and habenular commissure

Answer 7

interconnects posterior dorsal thalamic nuclei

Question 8

Fornix

Answer 8

• important white matter tract
• connects hippocampus to the hypothalamus via mammillary bodies
• relays cortical input to regulate neuroendocrine and autonomic systems

Question 9

Arcuate Fasciculus

Answer 9

connects Broca and Wernicke’s areas

-damage results in conduction aphasia

Question 10

Uncinate fasciculus

Answer 10

• major frontotemporal tract that connects orbitofrontal cortex to the anterior temporal lobes
• plays an important role in social cognition and language