vertebrate development Flashcards
stages of embryotic development
cleavage, blastula formation, gastrulation, neurulation
cleavage (frog)
rapid division of the zygote into a MORULA (solid ball of cells)
*** more rapid in animal pole
animal vs vegetal pole
more yolk in vegetal, slower division
blastula (frog)
hollow ball of cells
blastula formation (frog)
continued division to form blastula (with blastocoel inside)
gastrulation (frog)
cells from outer surface migrate in through blastopore, displacing the blastocoel and forming the archanteron.
3 embryonic germ layers are established - eventually outside lined by ectoderm, archanteron lined with endoderm, and other is mesoderm
medial region of the mesoderm gives rise to the notochord, on the dorsal midline of the embryo
mesoderm generally gives rise to
many regions of the skeleton, most muscles, notochord, circulatory system
endoderm generally gives rise to
lining of the digestive tract as well as liver, pancreas, gall bladder, digetive glands, lungs, swim bladder, and urinary bladder
ectoderm generally gives rise to
epidermis and many skin glands, as well as nervous system and many sensory organs
neural plate formation (frog)
notochord signals for ectoderm dorsal to notochord to differentiate into neural plate ectoderm
neurulation (frog)
neural plate ectoderm bends, forming neural groove surrounded by neural folds
folds fuse into hollow neural tube (inside is neurocoel), gives rise to central nervous system
neural crest cells from dorsal region of tube (what was connecting to neural plate ectoderm) separate, become mesenchymal
differentiation of mesoderm
AFTER gastrulation, meso diff into EPIMERE, MESOMERE, HYPOMERE
epimere mesoderm forms___ and differentiates into ____
somites
dermatome (most dorsal), myotome (my how far from midline), sclerotome (sneakily close to notochord)
hypomere mesoderm is located where in the embryo (frog)
to the right and left of the archanteron
coelom - how does it form and what is it?
two spaces which give rise to the major body cavities in adults
the hypomere mesoderm to the right and left of the archanteron differentiate into somatic on the outside, splanchnic on the inside and the space between them is the coelom
