Cerebrum Flashcards
Cerebral cortex
Surprisingly thin layer of grey matter
2-4 mm thick
Gyri
AKA convolutions
The folds in the cerebral cortex
Fissures
Deepest grooves between folds of cerebrum
Longitudinal (between right and left hemispheres. Falx cerebri)
Transverse (between cerebrum and cerebellum. tentorium cerebelli))
Sulci
Shallow grooves between gyri
Lateral cerebral sulcus
Between frontal and temporal lobes
Central sulcus
Between frontal and parietal lobes
Parieto-occipital sulcus
Between parietal and occipital
Precentral gyrus
Anterior to central sulcus
Primary motor cortex
Postcentral gyrus
Posterior to central sulcus
Primary somatosensory cortex
Insula
“5th lobe”
Deep to parietal, frontal and temporal lobes. Within lateral cerebral sulcus
Three types of cerebral white matter:
- Association tracts
- Commissural tracts
- Projection tracts
Association Tracts
Axons that conduct impulses between gyro in the same hemisphere
Commissural Tracts
Axons that conduct impulses between corresponding gyri in different hemispheres
3 major commissural tracts
- corpus callosum
- anterior commisure
- posterior commisure
Projection Tracts
Axons that conduct nerve impulses between the cerebrum and lower parts of the CNS
Largest fibre bundle in the brain
Corpus callosum
Basal Nuclei
Three grey matter nuclei within each cerebral hemisphere
- globus pallidus
- putamen
- caudate nucleus
Interface between cortex and limbic system.
Receives input from cerebral cortex, and send output to motor cortex
Lentiform Nucleus
In basal nuclei
globus pallidus + putamen
Corpus Striatum
In basal nuclei
lentiform nucleus + caudate nucleus
Claustrum
Thin sheet of grey matter next to putamen
Function unknown
Functions of basal nuclei
- regulates initiation and termination of movement
- suppresses unwanted movement; regulates muscle tone
- controls nonconscious contractions of skeletal muscle
- influence some cognitive processes (initiating/terminating attention, memory, planning)
Axons from substantial nigra terminate
In caudate nucleus and putamen
Limbic System
“emotional brain”
Also involved with olfaction and memory
Composed of: Limbic lobe Dentate gyrus Amygdala Septal nuclei Mammillary bodies (hypothalamus) Anterior and medial nuclei (thalamus) Olfactory bulbs Fornix, stria terminalis, stria medialis, medial forebrain bundle and mammillothalamic tract
Hippocampus
In limbic lobe (within parahippocampal gyrus)
Strongly involved in memory
Can undergo neurogenesis
What two parts of the limbic system can undergo neurogenesis?
Hippocampus
Dentate gyrus
What part of the brain is involved in fear conditioning?
Amygdala
