Q. Signals for parturition originate from :
(a) Placenta only
(b) Fully developed foetus only
(c) Both placenta as well as fully developed foetus
(d) Oxytocin released from maternal pituitary
Solution :
Correct option :C
Parturition is an induced Complex neuroendocrine mechanism. In this signals are originated from a fully developed fetus and placenta. This lead to mild uterine contractions and hence fetal ejection reflex. Then oxytocin is released from maternal pituitary and it acts on uterine muscles leading to strong uterine contractions. This further continues to stronger and stronger contractions. As a result, the baby is expelled out of the uterus with placenta through the birth canal. So, the correct option is Both placenta as well as fully developed foetus