Human Embryonic Ventricular Timeline
|
Week
|
Carnegie Stage
|
Event
|
Week 4
|
Stage 11
|
appearance of the optic ventricle. The neural groove/tube space is initially filled with amniotic fluid.
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Stage 12
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closure of the caudal neuropore, onset of the ventricular system and separates the ependymal from the amniotic fluid.
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Stage 13
|
cavity of the telencephalon medium is visible.
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Week 5
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Stage 14
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cerebral hemispheres and lateral ventricles begin, rhomboid fossa becomes apparent.
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Stage 15
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medial and lateral ventricular eminences cause indentations in the lateral ventricle
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Week 6
|
Stage 16
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hypothalamic sulcus is evident.
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Stages 17 - 18
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interventricular foramina are becoming relatively smaller, and cellular accumulations indicate the future choroid villi of the fourth and lateral ventricles.
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Week 7
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Stage 18
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areae membranaceae rostralis and caudalis are visible in the roof of the fourth ventricle, and the paraphysis is appearing.
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Stage 19
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choroid villi are visible in the fourth ventricle, and a mesencephalic evagination (blindsack) is visible
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Week 8
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Stage 20
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choroid villi are visible in the lateral ventricle.
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Stage 21
|
olfactory ventricle is visible.
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Stages 21-23
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lateral ventricle has become C-shaped (anterior and inferior horns visible). Recesses develop in the third ventricle (optic, infundibular, pineal).
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Reference: O'Rahilly R. and Müller F. Ventricular system and choroid plexuses of the human brain during the embryonic period proper. (1990) Amer. J Anat. 189(4): 285-302. PMID 2285038
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