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23 Cards in this Set
- Front
- Back
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what are the names of the prominent flexures that develop and at how many weeks?
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6 weeks
cephalic, pontine, cervical |
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what are the 3 primary vesicles and why do they form?
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cranial to caudal
prosencephalon mesencephalon rhombencephalon develop b/c of massive cell proliferation at rostral end |
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what does the prosencephalon give rise to?
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telencephalon (hemispheres, basal ganglia)
diencephalon (thalamus, hypothalamus and retina) |
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where is CN I derived from? what type of myelinating cells would be present?
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derived from CNS; oligodendrocytes
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what is the ventricle formed by proliferation of the telencephalon?
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lateral
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where does the 3rd ventricle develop?
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in cavity of diencephalon
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what forms in the cavity of the mesencephalon?
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cerebral aquaduct
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what does the rhombencephalon give rise to?
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metencephalon-pons, cerebellum
myelencephalon-medulla |
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where does the 4th ventricle develop?
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in the cavity of the rhombencephalon
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where is the pontine flexure and what is its significance developmentally?
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in caudal brainstem
pushes down during development to flatten the walls of the fourth ventricle; ventral motor areas-> medial dorsal sensory areas-> laterally (in brainstem) |
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what is the result of the anterior neuropore failing to fuse?
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anencephaly
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how does spina bifida develop?
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failure of the posterior neuropore to close (6 weeks)
take folic acid! |
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where does fusion of the neural tube begin?
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cervical region then moves cranial and caudal
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what is the sulcus limitans?
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divides spinal cord into alar/basal (dorsal/ventral)
becomes intermediate zone |
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what is another name for dorsal/ventral?
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dorsal = ALAR
ventral = BASAL |
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what is an alpha motor neuron and where do they synapse?
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lower motor neuron
synapse on mm. |
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where do cortical neurons originate?
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in ventricular zone, then move out
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how many cell layers are in the cortex? which is the older, youngest?
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6 layer numbered 1-6, 1 being further from the ventricles and 6 being the closest.
6 oldest; 1 youngest (moving out of suburb) different cells at different layers have different fxns; timing is imp in det cell fxn |
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how do developing neurons migrate?
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along the processes of radial glial cells
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when does neuronal migration peak? when is it completed?
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peaks 11-15 weeks
completed by week 24 |
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what is one of the reasons for MR in fetal alcohol syndrome?
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alcohol interferes with neuronal migration -> abnormal layering of cortex and cerebellum
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what is microcephaly the result of?
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abnormal neuronal proliferation and/or survival
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what is lissencephaly?
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"smooth brain"
thick cortex but only 4 layers genes involved regulate microtubules (cell shape, motility) |
