Embryogenesis/Pregnancy Recognition

Question 1

Define Conceptus what stage is next?

Answer 1

The stage between zygote and tissue formation. in which after tissue formation we call it an embryo.

Question 2

During embryogenesis when are the cells totipotent ?

Answer 2

After the mitotic division of half parental cytoplasm gives two blastomeres and these further divide up until 16cell stage. These stages of blastomere mitotic division is a period of totipotency. time that identical twins an develop.

Question 3

When is a cell @Morula. Define cell structure(s) define the steps to becoming a blastocyst

Answer 3

when cells reach the 16,32-cell stage the permeability of the outer-cell membrane to sodium allows water to follow and create fluid filled space. inner cells= gap junctions , outer= tight junctions. Fluid filled space is blastocoele and morula has evolved into a blastocyst

Question 4

Describe the process of hatching

Answer 4

The inner cell mass pushed abasing the trohoblast wall with ZP still intact. the trophoblast release enzymes to break down ZP wall.

As blastocyst develop (w. fluid) = hatching out of ZP and fluid in uterine lumen.

Question 5

give the three ways that the conceptus regulates access to progesterone

Answer 5

conceptus:
1. sends signal to prolong CL
2. C:L maintains until placental
3. embryo maintains CL through whole pregnancy.

Question 6

Cytotrphoblast versus syncytiotrophoblast

Answer 6

Cytotrophoblast = inner cell mass that becomes the placenta /choid

synt= trophoblast multinucleate mass (outer layer)