| Question |
Answer |
| the first movement of the embryonic cell populations into 3 layers is what phase? |
gastrulation |
| the cranial end of the primitive streak is called what? what is the caudal end called? |
prechordial; cloacal |
| what organizes the embryogenic patterning and tissue differentiation? |
hensen's node |
| what direction does primitive streak grow in? |
posterior to anterior |
| if the primitive streak cells persist, what can happen? |
sacrococcygeal teratomas |
| what do anterior-bound cells that are migrating between the epiblast and hypoblast form? |
cardiogenic and notochord plate |
| because the first cells to pass through the primitive streak reach the anterior side first, what happens? |
embryos develop anterior to posterior |
| a hollow, cartilaginous rod that extends through the midline is called what? |
the notochord |
| when does the notochord degenerate? |
apoptosis-sclerotomes develop into vertebrae |
| some portions of notochord persist as what structure in adults? |
nucleus pulposis |
| epiblast cells that invaginate through primitive pit extend anteriorly to form what structure? |
notochordal process |
| what comprises the the prechordal plate? |
adherent hypoblast and epiblast cells |
| during regression, the notochordal process fuses with what? |
the underlining endoderm |
| the transitory channel between amniotic cavity and yolk sac is called what? |
the neuroenteric canal |
| the once-tubular notochordal process flattens to form what? |
the notochordal plate |
| the notochordal plate folds in to become what? |
the notochord |
| Epiblastic cells invaginate to form a narrow groove along the posterior medial line called what? |
primitive groove |
| After invagination, primitive groove cells separate from the epiblast layer and migrate into the space between what layers? |
epiblast and hypoblast |
| cells that do not pass through the primitive groove become what germ layer? |
ectoderm |
| cells that displace the hypoblast become what cells? |
endoderm |
| The cells that occupy the space between the endoderm and ectoderm generate what layer of cells? |
mesoderm |
| the notochord is derived from what structure? |
hensen's node |
| the lumen that forms in the notochordal process is called what? |
notochordal canal |
| does the notochordal plate fold anteriorly-to-posteriorly or posteriorly-to-anteriorly to become the notochord? |
anteriorly-to-posteriorly |
Ch.18 LTI-MA 509
