Cortex and localization Flashcards
what increases in the newborn: number of neurons or neuron connections? what is this period called
connections. critical period (first 2 yrs). Neurons may actually decrease in # (synaptic pruning).
fxn of layers 2,3
thinking neurons, short connections although 3 sends some thru corpus callosum. mostly stellate
fxn of layer 4
thalamic input layer
fxn of layer 5
major output layer. Pyramidal (long) neurons. Gives rise to corticospinal and bulbar tracts
fxn of layer 6
reciprocal connection to thalamus.
three major exceptions to uniformity of neocortex
sensory: big 4, small 5. Motor: big 5, small 4. Association (fasciculi): layers are equal
describe path for touch, pressure, vibration from body: name of path? size and kind of fibers?
dorsal column, medial meniscus; larger Aalpha ad Abeta axons
descibe path for pain and temp from body: name of path, size and kind of fibers
anterolateral or spinothalamic; small Adelta and C axons
what inputs do medial and lateral geniculate nuclei receive
lateral- vision from retina then to clacarine cortex via optic radiations. medial- hearing from inferior brachium then to heschels gyrus
basic fxns of frontal lobe
movement, planning, personality, speech (left side)
basic fxns of parietal lobe
somatic sense, spatial, attention, multimodal sensation
basic fxns of temporal lobe
hearing, sensory memory, language (left side), visual processing
difference b/w brocas and wernickes aphasia
brocas is non fluent, left fontal lobe, no loss of understanding. wernickes is fluent, left temporal lobe, understanding is impaired
damage to what area might result in hemineglect
right sided lesion gives left hemineglect. not true for left sided lesions
lateral vs medial descending systems
lateral is more distal musculature (corticospinal, rubrospinal. Medial is more proximal musculature (vestibulospinal, reticulospinal)
