lectures - neurulation

neurulation is...

formation of spinal chord and brain precursors from epiblast ectoderm

when does neurulation begin

during primitive streak regression in gastrulation phase

nervous tissue is of what origin

ectoderm origin

what is the end goal of neurulation

formation of neural tube

define neural tube

rudiment of CNS

the neural tube is specific to

chordates

what kind of signals are used during neurulation

morphogens like chemicals, env. changes, ionic changes, pH changes

how/why do mesoderm cells become notochord

mesoderm cells under Hensen's node get induction messages from HN to det and diff into the rod like notochord

where is the notochord location wise

under the midline of epiblast

what does the notochord induce

induces epiblast ectoderm to initiate CNS formation

what are the effects of notochord induction on epiblast ectoderm

notochord messages epiblast ecto above the noto to det and diff to start formation of the neural plate

is the notochord temporary

yes

what does the notochord become encased in

vertebrae

what is the neural plate

notochord induced epiblast ectoderm cells

first steps of CNS formation

how is the neural tube formed

invagination of neural plate

step by step, how is neural tube made

1. notochord induces epiblast ectoderm to become neural plate cells

2. neural plate bends into neural groove (V shaped)

3. neural groove closes/pinches off forming neural tube

what happens to cells within the neural tube

cells prolif and diff into CNS

what do the anterior cells of the neural tube do

thicken and constrict to form presumptive brain

what do the posterior cells of the neural tube do

remain tube like to form spinal cord