White Matter Pathways Flashcards
what are commisural pathways?
white matter fiber bundles that bridge the midline and connect identical cortical structures in the opposite brain hemispheres
what are association fibres?
white matter fiber bundles that connect different cortical regions within the same hemisphere
what are projection fibres?
white matter fibre bundles that connect a cortical region to lower parts of the brain or spinal cord
what is the main function of commissural pathways?
ensure integration of functions between left and right structures of the brain
what is the main commissural pathway that connects the right and left hemisphere?
corpus callosum
what does the anterior commussure connect?
inferior and middle temporal gyri and olfactory regions of each side
afferent projection fibres convey what?
sensory impulses to the cortex
efferent projection fibres convey what?
motor impulses away from the cortex
what does the anterior commissure connect?
temporal lobes
what is the anterior commissure’s role?
- involved in sensation of sharp pain and processing smells, emotion, speech, hearing and memory
where is the posterior commussure located?
crosses the midline on the dorsal aspect of the upper end of the cerebral aqueduct
what is the role of the cerebral aqueduct?
important in the bilateral pupillary light reflex
where is the habenular commissure located?
sits in front of the pineal gland
what does the habenular fissure connect?
habenular nuclei
what does the hippocampal commissure connect?
connects the fornix
what do short association fibres connect?
adjacent gyri
what do long association fibres connect?
distant parts of the brain
what does the superior longitudinal fasciculus connect?
connects all four lobes
what are the 3 parts of the superior longitudinal fasciculus?
- SLF 1 - involved in proprioception
- SLF 2 - visual perception
- SLF 3 - transfers somatosensory info
what does the arcuate fasciculus connect?
temporal + parietal lobe with frontal lobe
Broca’s and Wernicke’s area
which association fibres connect Wernicke’s and Broca’s area?
arcuate fasciculus
where is the cingulum located?
underneath the cingulate gyrus
what does the uncinate fasciculus connect?
hippocampus and amygdala with the inferior frontal lobe
what association fibres connect the hippocampus and amygdala with the inferior frontal lobe?
uncinate fasciculus
what does the fornix connect>
hippocampus to the mammilary bodies
the hippocampus is connected to the mammilary bodies by what association fibres?
fornix
what is the internal capsule?
an area in the brain, through which all the fibres that go to and from the cortex travel
what are the projection fibres?
ascending and descending tracts
what are the 3 main areas of the internal capsule?
- anterior limb
- genu
- posterior limb
name a tract that runs through the anterior limb of the internal capsule
frontopontine tract
name a tract that runs through the genu of the internal capsule
corticonuclear tract
name a tract that runs through the posterior limb of the internal capsule
- corticospinal tract
- optic radiations
- acoustic radiations
Label the commissural fibres
Label the corpus callosum
Label the habenular commissure
Label the fornix and hippocampal commissure
Label the internal capsule
Label the long association fibres
