Question

(i) Name the organ that forms a connection between foetus and the uterus of a pregnant human female.

(ii) How does it support both nutrition and hormonal regulation ?

Hint:

The organ is the placenta; link its exchange role with its role as a temporary endocrine gland.

Answer 1

Step 1: Identify the organ (part i):
After implantation, finger-like chorionic villi grow out of the trophoblast. They interdigitate with uterine tissue and form a structural and functional unit between the developing embryo and the maternal body. This unit is the placenta. The placenta is joined to the foetus by the umbilical cord.

Step 2: Role in nutrition (part ii):
Oxygen and nutrients pass from the maternal blood to the foetal blood across the placenta. Carbon dioxide and other waste materials pass from the foetus to the maternal blood for removal.
So the placenta supplies food and oxygen and clears the waste of the foetus.

Step 3: Role in hormonal regulation (part ii):
The placenta also works as a temporary endocrine gland. It produces hormones such as human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens and progestogens. Relaxin is also made in the later stage of pregnancy.
These hormones keep the pregnancy going and support the growth of the foetus and the changes in the mother.

Final Answer:
(i) The organ is the placenta. (ii) It passes nutrients and oxygen to the foetus and removes wastes, and it secretes hCG, hPL, estrogens, progestogens and relaxin.