What are the routes of migration of neural crest cells?
- 1. Sensory ganglia
- 2. ANS ganglia
- 3. Adrenal neurosecretory
- 4. Non-neural (melanocytes)
What is the sulcus limitans?
- spinal/brainstem organization
What are the 5 secondary vesicles?
- Telencephalon-cerebral cortex, basal ganglia, optic nerves
- Diencephalon-thalamus & hypothalamus
- Mesencephalon-midbrain, basal ganglia (substantia nigra)
- Metencephalon-pons & cerebellum, rostral cranial nerves
- Myelencephalon-medulla, caudal cranial nerves
- Prosencephelon: Telencephalon & Diencephalon
- Rhombencephalon: Metencephalon & Myelencepthalon
What are the 4 flexures?
- pontine-doesn't persist, organize 4th ventricle & positions of alar and basal plates
What are the functional divisions of the cerebral cortex?
- frontal-higher cognitive functions
- parietal-spatial and navigation
- temporal-auditory, speech, memory
What is the pathway of sensory information?
- DRG->spinal->brainstem->thalamus->cerebral cortex
What are ependymal cells?
ventrcular surface, choroid(epithelial) plexus
What is the diff btwn oligodendrocytes and schwann?
- oligo myelinate multiple
- schwann-single axon
What are 2 ways to increase conductance speed?
axon diameter, insulation(myelination)
What are microglia?
- resident macrophages in CNS
- derived from blood monocytes
- enlarge, proliferate, phagocytose and secrete cytokines from insults
What are the brain barrier systems?
- 1. Blood-brain: tight junctions of endothelial
- 2. Choroid cell: maintains CSF barrier
- 3. Arachnoid: maintains fluid barrier
- 4. Perineurial: surrounding peripheral nerves
Within the meninges where are the major vessels that supply the brain?
- in the subarachnoid space, send capillaries to brain tissue that are monitored by ASTROCYTES
- Astrocytes have foot processes that surround capillary
- exchange occurs in capillary endothelial tight junction with itself
What are mengial extensions of peripheral nerves?
- perineurium (around bundles of axons)
- epineurium (around clusters of bundles)
What is the ventricular system of the CNS?
- fluid filled cavities, lined with ependymal cells
- choroid plexus: tissue made of choroid epithelium(single, cuboidal w microvilli & mitochondria)and stroma consisting of CT and vessels(fibroblasts, small arteries, venous sinuses, fenestrated capillaries), secretes CSF
- plexus found in lateral ventricles, 3, 4th ventricles
What is the flow pattern of CSF?
- 1. choroid plexus
- 2. lateral ventricles
- 3. intraventricular foramen (Monro)
- 4. 3rd ventricle
- 5. cerebral aqueduct
- 6. 4th ventricle
- 7. foramen of magendie & Luschka
- 8. subarachnoid space
- 9. CNS
- 10. arachnoid villa (pressure)
- 11. sagital sinus & venous circulation (internal jugular)
What is hyprocephalus?
- birth defect 1:500-1000
- most common pediatric brain surgery
- fatal if not treated
- treatment: implant shunt to drain CSF to circulation