CNS Development Flashcards
when does the human brain begin development?
during week 3
what can be caused If placental function is lacking?
IUGR
when is the embryonic period?
from conception to week 9
what are the initial two layers of the embryo?
epiblast
hypoblast
what is found in the middle of the two layered embryo?
primitive streak
primitive node
what are the three layers of the three layered embryo/
ectoderm
mesoderm
endoderm
what does the ectoderm form?
skin
nails
hair
neural tissue
what does the mesoderm form?
muscle
bone
cartilage
vascular system
what does the endoderm form?
gut
respiratory system
what embryonic layer forms the neural tissue?
ectoderm
what is the first well defined neural structure that forms?
the neural tube
when does the neural tube form?
between days 20 - 27
how does the neural tube form?
neural progenitor cells form the neural plate, which folds in on itself to form the mural tube
what lines the inside of the neural tube?
neural progenitor cells
what is the inside of the neural tube called?
the ventricular zone
what does the hollow centre of the neural tube form?
ventricular system
central channel of the spinal cord
what does the rostral part of the neural tube form?
the brain
what does the caudal part of the neural tube form?
the spinal cord
when is the foetal period?
from week 9 til term
what determines the differentiation of neural tissue in the foetal period?
signalling molecules
what signalling molecules determines the function of neurones in the foetal period?
emx2
pax6
what do progenitor cells become when there is high Pax6 and low Emx2?
motor neurones
where are more motor neurones located?
the anterior brain
what do progenitor cells become when there is low Pax6 and high Emx2?
visual cortical neurones
where are more visual cortical neurones found?
the posterior brain
what is a smooth brain called?
lissencephaly
how does the brain start?
very smooth
gradually developed its folds
how do the sulci and gyri develop sequentially?
primary sulci
secondary sulci
tertiary sulci
what do neural progenitor cells divide into?
initially = two identical neural progenitor cells
then into one progenitor cell and one neuron
can neurones divide?
no
how many layers make up the neocortex?
six
