Which of these is not an important component of initiation of parturition in humans?
- Release of oxytocin
- Release of prolactin
- Increase in estrogen and progesterone ratio
- Synthesis of prostaglandins
Answer
(2) Release of prolactin
Solution
As per NCERT, parturition is induced by a complex neuroendocrine mechanism: signals from the fully developed foetus and the placenta induce mild uterine contractions (foetal ejection reflex), which trigger release of oxytocin from the maternal pituitary.
At the end of pregnancy the estrogen : progesterone ratio rises and prostaglandins are synthesised; both increase uterine contractions.
Prolactin is concerned with milk production (lactation), not with initiation of parturition.
∴ Release of prolactin is not a component of initiation of parturition.
Answer: (2)