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Related Flashcards
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Cards In This Set
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Why learn about the development of the nervous system
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1. Helps us understand the adult NS
2. Helps understand common congenital malformations |
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What are the steps of primary neurolation (neural tube formation)
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3rd week - chemical signals form neural plate
folds to become neural grove w/ neural folds end of 3rd week - folds fuse to become neural tube end of 4th week - neural tube is closed and neural crest cells are formed |
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What is the neural plate
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Thickened portion of ectoderm
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What does the neural tube form?
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Nearly entire CNS and the cavity inside tube gives rise to ventricular system
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What do neural crest cells do
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They give rise to a variety of cell types including much of the PNS (dorsal root ganglia -sensory neurons, autonomic ganglia, adrenal medulla, and some cranial nerves)
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What happens during the secondary neurulation?
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A secondary cavity forms into cells being the sacral spinal cord region
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What is the sulcus limitans?
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4th week - longitudinal groove in wall of neural tube
it separates the neural tube into dorsal and ventral halves |
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What is the alar plate?
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Posterior horn
sensory functions dorsal to sulcus limitans |
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What is the basal plate?
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Anterior horn
motor functions ventral to sulcus limitans |
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What are the three bulges (primary vesicles) in the neural tube and when do they develop?
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During the 4th week
Prosencephalon (forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain) |
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What are the five secondary vesicles in the neural tube, what are their neural derivatives, and when do they develop?
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During the 5th week
Telecephalon - cerebral hemispheres Diencephalon - thalmus, hypothalmus, retina, etc. Mesencephalon - midbrain Metencephalon - pons, cerebellum Myelencephalon - medulla |
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What is important about the cephalic flexure?
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It is between the midbrain and diencephalon
creates a bend in the neural axis |
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What is important about the pontine flexure
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Between the pons and medulla (caudal brainstem)
flattens neural tube so the sulcus limitan separates alar and basal plates (makes it so sensory neurons are more lateral rather than posterior) |
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When do the neurons and glial cells continue to form an dmigrate? and what happens after this?
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3rd-5th months; synaptogenesis
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What happens postnatally
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Synaptogenesis and myelination
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