Early Neural Development
This animation of early neural development from week 3 onward shows the neural groove fusing to form the neural tube.
View - Dorsolateral of the whole early embryo and yolk sac. Cranial (head) to top and caudal (tail) to bottom. Yolk sac is shown to the left.
- Beginning with the neural groove initially fusing at the level of the 4th somite to form the neural tube.
- Then closing in both directions to leave 2 openings or neuropores that close last
- cranial neuropore (anterior neuropore).
- caudal neuropore (posterior neuropore).
- These neuropores are the last region of the neural tube to close and be lost from the embryo surface.
- In humans, the cranial neuropore closes about 2 days before the caudal neuropore.
- Failure of these opens, or any part of the neural tube, to close are described as neural tube defects.
- The animation also shows as the embryo grows and folds it increases in size relative to the initial yolk sac. Note also the increasing number of somites over time.