developmental Flashcards
nonsense, know everything.
what is the name of the 36 cells after all cell division from zygote
morula
what makes up the late blastocyst
outside = trophectoderm
top, bottom = hypoblast
icm = epiblast
explain formation of the three germ layers
after multiple cell divisions, the blastocyst loses its outer ring of cells and becomes an granola, then there is a primitive strike that generates the ectoderm, mesoderm and endoderm
what is gastrulation
the formation of the three germ layers from the primitive streak and hensen’s node
where are ectoderm cells end up
nervous system, epidermis
where do mesoderm cells end up
heart, skeletal muscle, blood and bone
where do endoderm cells end up
epithelia of GI and respiratory tract, pancreases, thyroid
what are the key molecules in heart developmen
GATA, BMPs, Wnt inhibitors, Nsk2.5, Fgf
in general, how does the heart develop
at 21 days, there Is a fusion into primitive heart tube which then differentiates into the different parts until it become a heart at 35 days
how is miRNA involved in heart development
they control the expression of the differentiation factors needed for heart development
what are the key molecules in lung development
Tbx5, Wnt2, Wnt2b, BMP
describe formation of the lung
lung and trachea specification -> lung bud formation -> trachea formation
how are fgf and shh involved in lung development
they provide communication between epithelium and mesenchyme, Shh inhibits FGF10 cluster of mesenchyme cells which then separate and two new buds form
what are the signaling pathways in limn development
ZPA = zone of polarizing activity, Shh AER = apical ectodermal ridge, Fgf
what is the important of apoptosis during limb developmemnt
it allows for the formation of limbs like fingers through cell death
what is teratology
study of birth defect
what are teratogens
agents that produce birth defects
what is developmental toxicollogy
study of environmental chemical that cause birth defects
what is the incidence of birth defects
1/20 live births
15% spontaneous abortions
what is specification
programming of stem cells to develop along a particular pathway
what is differentiation
process by which an unspecialized cell matures to possess distinct function
what are the three types of stem cell specification
autonomous specification
syncytial specifiation
conditional specification
explain autonomous specification
cells develop along a particular pathway in the absence of any external influences
explain syncytial specification
nucleus divides but cytoplasm does not
