| 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.
|
| Stage 12
|
closure of the caudal neuropore, onset of the ventricular system and separates the ependymal from the amniotic fluid.
|
| Stage 13
|
cavity of the telencephalon medium is visible.
|
| Week 5
|
Stage 14
|
cerebral hemispheres and lateral ventricles begin, rhomboid fossa becomes apparent.
|
| Stage 15
|
medial and lateral ventricular eminences cause indentations in the lateral ventricle
|
| Week 6
|
Stage 16
|
hypothalamic sulcus is evident.
|
| Stages 17 - 18
|
interventricular foramina are becoming relatively smaller, and cellular accumulations indicate the future choroid villi of the fourth and lateral ventricles.
|
| Week 7
|
Stage 18
|
areae membranaceae rostralis and caudalis are visible in the roof of the fourth ventricle, and the paraphysis is appearing.
|
| Stage 19
|
choroid villi are visible in the fourth ventricle, and a mesencephalic evagination (blindsack) is visible
|
| Week 8
|
Stage 20
|
choroid villi are visible in the lateral ventricle.
|
| Stage 21
|
olfactory ventricle is visible.
|
| Stages 21-23
|
lateral ventricle has become C-shaped (anterior and inferior horns visible). Recesses develop in the third ventricle (optic, infundibular, pineal).
|
|
|
| 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
|
