cerebral hemisphere Flashcards
1
Q
Achicotex
A
- part of allocortex (ancient center)
- contains 3 layers of gray matter
- involved in memory and emtions
- HIPPOCAMPAL FORMATION
2
Q
Paleocortex
A
- Part of allocortex (ancient cortex)
- made up of 3-5 layers of gray matter
- PARAHIPPOCAMPAL GYRUS, uncus and the lateral olfactory gyrus (olfactory system)
3
Q
Mesocortex
A
- Part of allocrotex (ancient center)
- made up of 3-6 layers of gray matter
- cingulate gyrus and the insula
4
Q
describe Neocortex
A
- is the evolutionarily newer cortex (makes up 90% of cerebral cortex)
- made up of 6-layers present with regional variation
–> HOMOTYPICAL CORTEX = association areas (all 6 layers are present)
–> HETEROTYPICAL CORTEX = PRIMARY AREAS
1) agranular = primary motor cortex
2) granular = primary sensory cortex
5
Q
define pyramidal cells
A
- most abundant, 75% of cortical cells
- Long axons FORM WHITE MATTER TRACTS
6
Q
Fusiform
A
- Modified pyramidal
- Located in the DEEPEST cortical layers
- Axons PROJECT TO THALAMUS
7
Q
define Stellate (granule) cells
A
- Involved in integration
- Aspiny = INHIBITORY INTERNEURONS
- Spiny = EXCITATORY interneurons, located in layer IV of the gray matter
8
Q
Horizontal cells of cajal
A
- located in SUPERFICIAL most layer of gray matter
- Seldom seen or completely lacking in adult brain
9
Q
Cells of MARTINOTTI
A
- Interneurons
- located in DEEP LAYERS of the gray matter
10
Q
Association fibers
A
- Intracortical fibers = superior longitudinal fasciculus, uncinate fasciulus, occipitofrontal fasiculus
- Send projections WITHIN SAME HEMISPHERE (IPSILATERAL)
11
Q
Commissural fibers
A
- Commissural fibers = corpus callosum, anterior/posterior commissures
- TO/FROM OPPOSITE HEMISPHERE (CONTRALATERAL)
12
Q
Projection fibers
A
- Ex = crus cerebri, internal capsule
- TO/FROM CORTEX and SPINAL CORD = corticobulbar, corticothalamic, corticopontine
- INTERNAL CAPSULE
13
Q
Molecular layer (I)
A
- Synaptic area = axons and MOSTLY DENDRITES
- neuroglia and cells of cajal
- INTEGRATION (sends axons horizontally)
14
Q
External granular layer (II)
A
- Small pyramidal and STELLATE CELLS
- Axons and dendrites from deeper layers
- INTEGRATION (sends cells horizontally)
15
Q
External Pyramidal layer (III)
A
- Moderate size PYRAMIDAL cells
- EFFERENT LAYER (OUTPUT LAYER)
- Corticocortical fibers = association and commissural fibers