White Matter Pathways

Question 1

what are commisural pathways?

Answer 1

white matter fiber bundles that bridge the midline and connect identical cortical structures in the opposite brain hemispheres

Question 2

what are association fibres?

Answer 2

white matter fiber bundles that connect different cortical regions within the same hemisphere

Question 3

what are projection fibres?

Answer 3

white matter fibre bundles that connect a cortical region to lower parts of the brain or spinal cord

Question 4

what is the main function of commissural pathways?

Answer 4

ensure integration of functions between left and right structures of the brain

Question 5

what is the main commissural pathway that connects the right and left hemisphere?

Answer 5

corpus callosum

Question 6

what does the anterior commussure connect?

Answer 6

inferior and middle temporal gyri and olfactory regions of each side

Question 7

afferent projection fibres convey what?

Answer 7

sensory impulses to the cortex

Question 8

efferent projection fibres convey what?

Answer 8

motor impulses away from the cortex

Question 9

what does the anterior commissure connect?

Answer 9

temporal lobes

Question 10

what is the anterior commissure’s role?

Answer 10

• involved in sensation of sharp pain and processing smells, emotion, speech, hearing and memory

Question 11

where is the posterior commussure located?

Answer 11

crosses the midline on the dorsal aspect of the upper end of the cerebral aqueduct

Question 12

what is the role of the cerebral aqueduct?

Answer 12

important in the bilateral pupillary light reflex

Question 13

where is the habenular commissure located?

Answer 13

sits in front of the pineal gland

Question 13

what does the habenular fissure connect?

Answer 13

habenular nuclei

Question 14

what does the hippocampal commissure connect?

Answer 14

connects the fornix

Question 15

what do short association fibres connect?

Answer 15

adjacent gyri

Question 16

what do long association fibres connect?

Answer 16

distant parts of the brain

Question 17

what does the superior longitudinal fasciculus connect?

Answer 17

connects all four lobes

Question 18

what are the 3 parts of the superior longitudinal fasciculus?

Answer 18

• SLF 1 - involved in proprioception
• SLF 2 - visual perception
• SLF 3 - transfers somatosensory info

Question 19

what does the arcuate fasciculus connect?

Answer 19

temporal + parietal lobe with frontal lobe
Broca’s and Wernicke’s area

Question 20

which association fibres connect Wernicke’s and Broca’s area?

Answer 20

arcuate fasciculus

Question 21

where is the cingulum located?

Answer 21

underneath the cingulate gyrus

Question 22

what does the uncinate fasciculus connect?

Answer 22

hippocampus and amygdala with the inferior frontal lobe

Question 23

what association fibres connect the hippocampus and amygdala with the inferior frontal lobe?

Answer 23

uncinate fasciculus

Question 24

what does the fornix connect>

Answer 24

hippocampus to the mammilary bodies

Question 25

the hippocampus is connected to the mammilary bodies by what association fibres?

Answer 25

fornix

Question 26

what is the internal capsule?

Answer 26

an area in the brain, through which all the fibres that go to and from the cortex travel

Question 27

what are the projection fibres?

Answer 27

ascending and descending tracts

Question 28

what are the 3 main areas of the internal capsule?

Answer 28

* anterior limb * genu * posterior limb

Question 29

name a tract that runs through the anterior limb of the internal capsule

Answer 29

frontopontine tract

Question 30

name a tract that runs through the genu of the internal capsule

Answer 30

corticonuclear tract

Question 31

name a tract that runs through the posterior limb of the internal capsule

Answer 31

* corticospinal tract * optic radiations * acoustic radiations

Question 32

Label the commissural fibres

Answer 32

Question 32

Label the corpus callosum

Answer 32

Question 33

Label the habenular commissure

Answer 33

Question 34

Label the fornix and hippocampal commissure

Answer 34

Question 35

Label the internal capsule

Answer 35

Question 36

Label the long association fibres

Answer 36