Biology - Human Reproduction Question with Solution | TestHub
The expulsion of the fully developed foetus in human female is induced by the following EXCEPT:
Options:
Answer:
Solution:
Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and the placenta, which induce mild uterine contractions called foetal ejection reflex.
During this process, the foetal pituitary secretes ACTH, which stimulates the foetal adrenal glands to secrete corticosteroids. These hormones diffuse across the placenta and alter the estrogen to progesterone ratio, further promoting uterine contractions.
The level of human chorionic gonadotropin (hCG) reaches its peak during the first trimester to maintain the corpus luteum and then declines. It does not increase at the end of pregnancy and plays no role in inducing the expulsion of the foetus.
Answer: The increase in the level of hCG.
