L20 Organogenesis Flashcards
List the order of events of Developmental Embryology that give rise to an Embryo
Fertilisation, Cleavage, Gastrulation, Neurulation, Organogenesis
what is cleavage stage known as?
8-cell stage
what is a type of organogenesis?
neurulation
what is meroblastic give example
yolk stays intact example zebrafish
what is holoblastic give example
yolk is divided amongst nearby cells example humans
what does ectoderm later form?
neurons, skin, pigment cells
what does mesoderm later form?
somites, heart, mesenchyme, mesothelium, non-epithelial blood cells and coelomocytes
what does endoderm later form?
lungs, pharynx, esophagus, stomach, small intestine, colon, liver, pancreas, bladder, thyroid
how is gastrulation characterised
interaction of cells across 3 distinct germ layers
how is organogenesis characterised?
local interactions that allow definition and development of an organ - forming tissues
morphogenesis of structures
what morphogenic structures occur during organogenesis?
folding of neural tube, looping of heart, branching of lungs
what cells make the germ layers?
STEM cells/ somatic cells
what are germ cells?
sex cells
How does nervous system form?
on outer embryo body and then becomes internalised
what is notochord derived from?
dorsal lip of blastopore
how does neural plate form?
notochord signals ectoderm layer to thicken
what signalling molecule is secreted from notochord and is key in neural plate synthesis?
shh
where are neural crest cells?
above neural plate
what do neural crest cells give rise to?
PNS
where and how does a neuron undergo to specialise as a neuron cell?
undergoes neurogenesis in CNS
What signalling pathway has a role in lateral inhibition?
delta-notch pathway
what does delta-notch signalling pathway do?
inhibits neighbouring cells from differentiating
why is hox code neccessary?
to ensure the right shape of vertebrate forms in the right place
what happens if hox code is changed?
nerve projection changes
