blastogenesis

Question 1

what week does blastogenesis occur?

Answer 1

week 3

Question 2

what happens during blastogenesis? (just the events)

Answer 2

• formation of the trilaminar embryo
• beginning of gastrulation
• formation of paraxial, intermediate, and lateral plate mesoderm of somitomeres and somites

Question 3

what happens in the beginning of gastrulation?

Answer 3

• formation of primitive node/pit/streak
• formation of neural groove
• formation of neural plate
• formation of notochord

Question 4

where does the primitive streak originate? (germ layer)

Answer 4

the epiblast

Question 5

during gastrulation, what happens to the epiblast cells?

- 3 things

Answer 5

• cells detach and invaginate to an area between the epiblast and hypoblast layers –> this is the mesoderm layer
• some cells detach and migrate even further and displace the hypoblast –> this is the endoderm layer
• some cells remain in the epiblast –> ectoderm