Question

How does the embryo get nourishment?
Answer in about 50 words..

Answer 1

Its in mother's body. She's the source of her nourishment. ... Whatever nutrients, minerals etc reach placenta through mother's blood, will be transported to foetus via umbilical cord. Also it facilitates the removal of waste material.

Answer 2

Hey Friend,

Right after the implantation, three extra-embryonic membranes (chorion, allantios, amnion) are formed! They are protective in function and support the blastocyst (ball of mass of repeatedly divided zygote). 
Chorion and allantios form allanto-chorionic placenta which helps in exchange of nutrients, oxygen and excretory material with the maternal blood.

Then, amniotic fluid protects the embryo from mechanical shocks. It also prevents the sticking of foetus to the amnion (amniotic sac).

Placenta is highly important, it acts as a
(i) respiratory organ - supplies oxygen to foetus
(ii) nutritive organ - provides food and minerals to the foetus
(iii) excretory organ - removes carbon dioxide and nitrogenous waste from the blood of foetus
(iv) endocrine gland - produces hormones like oestrogen and proesterone.

Hope it helps!