3. DEFINITION
The series of events that occur in the 3th
week of fertilization in which there is the
transformation of neural plate into the
neural tube is called neurulation.
4. ONCE INDUCTION FROM NOTOCHORD
BELOW , THE SLIPPER SHAPED
NEURAL PLATE GRADUALLY EXPANDS
TOWARDS PRIMITIVE STREAK ..
5. BY THE 3RD WEEK ,THE LATERAL EDGES
OF NEURAL PLATE BECOME ELEVATED
AND FORM NEURAL FOLDS AND
DEPRESSED MID REGION THAT FORMS
NEURAL GROOVE. AFTER WHICH NEURAL
CREST CELLS DETACH AND NEURAL TUBE
FORMS.
6. A. Thickening of surface ectoderm
causes neural folds to approach each
other which forms a depressed mid
region neural groove.
B. Neural crest cells are pinched
off during this process and give rise
to multiple derivatives.
C. Neural tube formed gives rise to spinal
cord and brain
