Subcortical Fibre Tracts Flashcards
Boundaries of frontal lobe
Dorsolateral surface: Central sulcus (posterior) and lateral/Sylvian fissure (inferior) Medial surface: corpus callosum (inferior) to central sulcus
Boundaries of parietal lobe
Dosolateral surface: Anterior = central sulcus; Inferior = lateral sulcus; Posterior = upper half of arbitrary line connecting parieto-occipital sulcus to the pre-occipital notch Medial: Frontal lobe = anterior boundary; Parieto-occipital sulcus and corpus callosum = posterior and inferior boundaries
Boundaries of temporal lobe
On lateral surface: Superior boundary = lateral sulcus and its posterior projection, Posterior boundary = lower portion of arbitrary line connecting the parieto-occipital sulcus and the pre-occipital notch 2. On medial surface•Posterior boundary: imaginary line joining the pre-occipital notch andt he anterior end of the calcarine sulcus
Occipital lobe boundaries
- On lateral surface•Anterior boundary = line joining the parieto-occipital sulcus and the pre-occipital notch On the medial surface:Anterior boundary = the posterior borders of the parietal and temporal lobes
Which structures are found in limbic lobe?
1) cingulate gyrus; 2) parahippocampal gyrus 3) hippocampal formation
What is the isthmus
Strip of cortex connecting parahippocampal gyrus to the cingulate gyrus
What is BA4
Primary motor area -precentral gyrus, presntral sulcus, central sulcus)
What is BA 6
premotor or motor association area
What is inferior part of BA 8
Frontal eye field - cortical control of gaze
What are BAs 3,1,2 involved in
Primary somatosensory cortex (post-central gyrus)
What are BAs 5,7, and 40 involved in?
Somatosensory association area – superior parietal lobules extending to medial surface
What are BAs 41 and 42 involved in?
Primary association area; superior surgface of superior temporal gyrus; Heschl’s gyrus
BA 22 is involved in which sensation?
Audtion; secondary auditory cortex
Which primary area is contained within BA 17?
Visual - in walls of calcarine fissure extending onto lateral surface
Which BAs make up the visual association area?
BA 18 and BA 19
Which BA is involved in taste?
BA 43
Where is taste information integrated with olfactory info?
Orbital cortex of frontal lobe and amygdala
Which BAs are involved in Broca’s Area?
44 and 45; inferior frontal/angular gyrus (usually left hemisphere)
Which BAs are involved in Wernicke’s areas?
22 (superior temporal gyrus) and regions 39 and 40 around the end of the lateral sulcus into the parietal lobe
Which fibre tract connects broca’s and wernicke’s
Arcuate fasciculus
Which region is damaged in patients who have difficulty repeating words (conduction aphasia)
Arcuate fasciculus
Which region is damaged in patients who have difficulty producing individual words, syntax, grammar
Broca’s
Which region is damaged in patients who cannot comprehend speech and produce non-sensical wordcs
Wernicke’s
Which region is characterized by BAs 9, 10, 11, and 12?
Frontal association - connected w/ DM thalamus
Where do fibres from the upper visual field travel after reaching the lateral geniculate nucleus?
Lower bank of calcarine sulcus (V1)/BA17
Where do fibres from the lower visual field travel after reaching the lateral geniculate nucleus?
Upper bank of calcarine sulcus (V1/BA17)
Where are the frontal eye fields
What lies posterior to the frontal eye field
Motor-hand area
Which thalamic nucleus does auditory info from cochlea project to?
Medial geniculate nucleus
What is heschl’s gyrus
Contains A1; located transversely within lateral sulcus
Within which cortex is the gustatory area?
Insular
Which two lobes are involved in Wernickes area
Temporal and parietal
What is the non-dominant hemisphere responsible for in language
Melody, prosody, accent, tone of voice
Unimodal association cortex
Involved in higher-order processing of a single sensory of motor modality (e.g., SMA, sensory association area)
Heteromodal association cortex
Involved in integrating functions from multiple modalities (e/g. sensory and motor)
Are Broca’s and Wernicke’s hetero or uni-modal
Unimodal
What are heteromodal areas?
Frontal, parietal, and temporal association areas
Where do most commissural fibres cross the midline
Corpus callosum
Which region of CC connects parietal and posterior frontal lobes?
Body
Which region of the CC connects occipital lobes and posterior temporal lobes?
Splenium
What does the genu of the CC connect?
2 frontal areas
What are 3 commissural fibres?
1) CC; 2) anterior commissure; 3) posterior commissure
What do association fibres connect?
Cortical regions in the same hemisphere (short connect adjacent gyri, long connect other regions like arcuate)
Which fibres are in the anterior limb of the IC?
Corticopontine, thalamocortical (DM and Ant. nuclei)
What is the blood supply to the ANTERIOR limb of the IC
Lenticulostriate arteries (deep branches from ACA and MCA)
What fibres are carried in the genu of the IC?
Corticobulbar
What is the blood supply to the genu of the IC?
Lenticulostriate (deep branches from MCA) and anterior choroidal
What fibres are carried in the posterior limb of the IC?
corticopontine; corticospinal (localized) , thalamocortical (from VP, VL, VA)
What is the blood supply to the posterior limb of the IC?
Lenticulostriate (deep branches from MCA); PCA, anterior choroidal
What are projection fibres?
Fibres that originate in THALAMUS and project to cortex (via posterior IC) or originate in cortex and project to subcortical nuclei in the cerebral hemisphere, brainstem or spinal cord
