Signals for parturition originate from :
- Placenta only
- Fully developed foetus only
- Both placenta as well as fully developed foetus
- Oxytocin released from maternal pituitary
Answer
(3) Both placenta as well as fully developed foetus
Solution
As per NCERT, 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.
⇒ This triggers the release of oxytocin from the maternal pituitary, which causes stronger uterine contractions.
∴ Oxytocin is a response to the signal, not its origin.
Answer: (3)