Anatomy Flashcards
Secondary somatosensory and input
Superior bank of lateral sulcus
Input from IL VPLc and VPM, bilateral primary somatosensory (S1)
Output to IL S1 and primary motor
Homunculus is inverted
Brodmann primary somatosensory including input
Post central gyrus (3, 1, 2)
3a: muscle spindles
3b: cutaneous (skin)
1: muscle spindles and skin
2: deep joint receptors
Receptors -> medial lemniscus/spine thalamus tract -> VPLc/VPM -> 312
Face and tongue are bilateral
Primary visual cortex (V1)
Area 17, calcarine cortex
Input: LGB -> geniculocalcarine fibers along lateral ventricles (external Sagittal striatum) -> calcarine sulcus
Output: internal sagittal striatum -> corticofugal fibers -> superior colliculus and LGB
Macula goes to posterior 1/3 (occ pole)
Band of Baillarger in striate cortex is stripe of gennari visible to naked eye (layer IVb)
Secondary visual cortex (V2 and V3)
Area 18 and 19 (surrounds V1)
Input LGB and pulvinar
Lesion causes visual agnosia
Primary auditory cortex
Area 41 (heschl gyrus, on superior temporal gyrus in the temporal operculum) with association cortex area 42 surrounding it
Input: IL MGB (fibers pass through sublenticular ICA). Each cochlea goes BL but more CL then ILL
Ventral MGB: higher frequencies more medial
Trapezoid body in the pons is only auditory commissure needed for sound localization
Lesion: CL>IL partial deafness
Dominant Area 22 lesion: word deafness or sensory aphasia with normal hearing
Gustatory cortex
Area 43 (post central operculum next to tongue sensory area) Input: IL nucleus solitarius-> VPMpc -> 43
Vestibular cortex
Inferior parietal lobule near head part of S1
BL representation but slightly more CL
Primary motor cortex
Brodman 4, precentral gyrus; pyramidal cells of Betz (cortical layer 5)
Output to corticobulbar and corticospinal (BL to eye face and tongue); asp and glu
Input from IL VL and VLo, CL cerebellum, S1 (except area 3), supplemental motor cortex
Premotor cortex
Area 6a, anterior to motor cortex
Input from medial GP-> IL VApc, VLo, CM -> premotor
Motor control for responses dependent on sensory input
No deficit with UL lesion
Supplemental motor cortex (M2)
Area 6a, medial aspect anterior to M1, medial superior frontal gyrus
Output from IL 4, 5, 6, 7 and CL M2, b/l SC, caudate, put amen and thalamus
Input- bilateral
Lesion: HP or plegia, diminished spontaneous speech, may have volition all movt with effort
Frontal eye fields
Area 8, rostral to premotor in caudal middle frontal gyrus
Initiates saccades, stim causes CL eye deviation (IL controlled by area 17, occ eye center)
Output to rostral interstitial nucleus of MLF, interstitial nucleus of cajal, para median pontine reticular formation, superior colliculus
Does not go directly to cn 3, 4, 6
Lesion: impaired saccades esp if dominant hemisphere
Thalamus: anterior nuclear group
Regulates visceral function
Input: mamillothalamic tract, fornix
Output: cingulate gyrus via ant limb IC
Thalamus: mediodorsal group
Bren IML and periventricular grey
Integrates somatic and visceral activity, controls affective behavior, disconnected during prefrontal lobotomies
Input: amygdala, orbits frontal and temporal cortex
Output: frontal association cortex or prefrontal area
Reciprocal connections with frontal eye fields
Lesion: korsakoff psychosis
Thalamus: centromere all nucleus
Attention and arousal
Within IML
Input: area 4
Output: putamen, STN
Thalamus: Parafascicular Nuclei
Enclosed by IML
Arousal and wakefulness
Input: Area 6
Output: caudate
Thalamus: Rostral intralaminar nuclei
Enclosed by IML
Arousal and wakefulness
Input: RAS
Output: diffuse cortex
Thalamus: periventricular gray and massa intermedia
Output: amygdala and cingulate gyrus
In midline
Thalamus: lateral dorsal nuclei
Output: Cingular and supralimbic parietal lobe
Input: limbic areal
Thalamus: lateral posterior nucleus
Input: parietal lobe
Output: areas 5 and 7
Thalamus: pulvinar nucleus
Visual connections
Input: superior colliculus, reciprocal connections with occipital cortex, temporal and parietal loves
Output: inferior pulvinar to area 18, lateral pulvinar to area 19, medial pulvinar to superior temporal gyrus