Embryogenesis Flashcards
What are the stages of embryogenesis?
- Morulation
- Blastulation
- Implantation
- Gastrulation
- Neurulation
“My Baby Is Growing Nicely”
How long is the duration of embryogenesis?
embryogenesis occurs during the first 8 weeks after fertilization
When is the embryo referred to as the fetus?
at the 9th week post conception (ore 11th week after the LMP)
What is “cleavage?”
The single celled zygote undergoes multiple rounds of mitotic division
True or False - the zygote grows in size during the morula phase
False - the cell divides many times, but remains in the Synthesis and Mitosis division. It’s growing in cell number only.
When is the zygote considered a morula?
When it has divided into a ball consisting of 32 cells
What are the components of the blastocyst?
outer trophoblasts, an inner cell mass, and a fluid filled cavity called the “blastocoel”
Where does the newly formed blastocyst travel to?
it must leave the fallopian tube and migrate to the uterus - there it implants into the endometrium to continue developing
What gives rise to the chorion?
the trophoblasts
What does the embryonic stalk eventually form?
the umbilical cord
Where do the 3 germ cell layers develop?
cells from the inner cell mass differentiate initially into the bilaminar disc
Where do cells migrate out from on the germ layers?
from the primitive streak
What are the 3 main germ layers?
- ectoderm
- mesoderm
- endoderm
What does the ectoderm germ layer give rise to?
brain, spine, pituitary, cornea/lens, skin/hair/nails
What does the mesoderm germ layer give rise to?
muscle, bone, cardio/excretory/reproductive systems
