building a human Flashcards
week 1 of human development is concerned with-
formation of supporting tissues and implantation
what follows immediately after fertilisation
cleavage - rapid cell divisions without growth, dividing embryo into numerous small cells
cleavage generates the ….. - trophoblast is outer layer (interacts with uterus)
blastocyst
embryo is derived from …. of blastocyst
inner cell mass
inner cell mass rearranges to form 2 layers - blastodisc:
epiblast and hypoblast
….. is the process through which cells sort out to generate the body plan. inward movement of cell form the epiblast
gastrulation
germ layers (3)
endoderm, mesoderm, ectoderm
development proceeds from ….. to ….
anterior to posterior
development proceeds from ….. to ….
anterior to posterior
neurulation -
formation of neural tubule - starts anterior end, ends in posterior
neural crest gives rise to ….. NS, pigments and in head skeleton
PNS
the ….. is reduced in mammals but has important developmental roles. lost in childhood
notochord
somites are blocks of
mesoderm
somitogenesis - bud off from the … part of the presomitic mesoderm
anterior
neural crest migration and motor nerves are organised by the internal subdivision of the …
somites
derivates of the mesoderm - somites form
sclerotome (skeletal tissue)
myotome (muscle)
dermatome (dermis)
kidney and gonads - which germ layer
mesoderm
defects in somitogenesis results in
scoliosis
endoderm is the source of much of the
viscera
-foregut, midgut, hindgut
bones of the skull derived from both
neural crest and mesoderm
neural tube and neural crest - which germ layer
and which week of development is neural tube formed
ectoderm
3rd and 4th week of gestation
neural tube and neural crest gives rise to
brain, spinal cord, PNS
notochord - which germ layer
and which week of development
mesoderm, by beginning of 4th week
-vertebrae development
somitogenesis
somites bud off from anterior of presomitic mesoderm to posterior
