Wk1 Flashcards
3 main germ layers in development
endoderm
mesoderm
ectoderm
mitosis is the process of __
cell division
what is the first stage of the embryo
morula
what stage of embryonic development starts to accumulate liquid on the inside?
blastocyst
what are the two main layers of the bilaminar embryo?
epiblast
hypoblast
where is an embryo generated from?
epiblast
where do extra embryonic cells originate?
hypoblast
what is gastrulation?
the stage when the embryonic disk collapses in on itself to form the embryonic (germ) layers
in gastrulation, cells fold around the __
midline
in gastrulation, cells on the surface of the ___ move ___
epiblast
inwardly
what does the ectoderm form? 2
skin
nervous system
what does the mesoderm form? 5
muscle connective tissue blood cells urogenital system most internal organs
what does the endoderm form? 2
respiratory and digestive tubes
where does the mesoderm form?
in between the ectoderm and endoderm
early nutrition that feeds the embryo comes through the ____ from the ___
vitelline duct
yolk sac
what happens in neurulation?
the ectoderm folds in on itself to create a neural tube
on which orietnation of the embryo does the neural tube form?
dorsal ( back)
how early is the neural tube starting to develop? when is it complete?
21 days
24-25 days
the neural tube closes like __ towards ___
a zipper each end (having started in the middle)
where does the neural tube form from?
ectoderm
a neural tube will close when the ___ meet
neural folds on the surface of the ectoderm
what comes from the hollow centre of the neural tube?
CSF
def neural plate (in development)
region of the ectoderm that will form the neural tube
what happens to the ectoderm layer once the neural tube has closed?
it will form skin
in what way does the nervous system arise from the ectoderm?
ectoderm forms the neural tube and the NS comes from this.
where are neurons of the Nervous system generated from in embryo?
neural tube (not ectoderm)
what happens to the neural fold once closed?
they become neural crest cells that go on to form bone, cartilage, nerves, and hair
how is hair important for developing a head and a face?
it reflects the compactness of sensation nerves in the brain, like nose and eyes etc. other animals without hair, like jellyfish, have more distributed nervous systems like a web instead of brain
what is produced at the ventral aspect of the neural tube?
SHH
the notocord produces a protein called ___
SHH