Embryonic structures-function

[meant2be10]

I'm getting confused about the embryonic structures. I feel like different sources all overlap what they say the function of each structure is. Between the different websites I have used it seems like all three play a role in gas/nutrition/excretion exchange but in my practice questions it seems like there should only be one correct response per structure.

Does anyone have a clear discription of allantois/chorion/placenta?

---

Members don't see this ad.

 

[Troyvdg]

I'm getting confused about the embryonic structures. I feel like different sources all overlap what they say the function of each structure is. Between the different websites I have used it seems like all three play a role in gas/nutrition/excretion exchange but in my practice questions it seems like there should only be one correct response per structure.

Does anyone have a clear discription of allantois/chorion/placenta?

they all have similar descriptions because they all deal with the placenta/umbilical cord

placenta- responsible for the exchange of food, oxygen, waste, and water
chorion- is where placenta formation begins, and it surrounds the amnion
allantois- develops as an outpocket of the gut/ blood vessels of the allantoic wall enlarge and become the umbilical cord

you can mainly see the difference between chorion and allantois in eggs.

and in eggs,
chorion- lines the inside of the shell and allows for gas exchange
allantois- is invovled in respiration and excretion through blood vessels