Question

What is parturition? Which hormones are involved in induction of parturition?

Answer 1

Parturition is the act of giving birth to the young; childbirth. Fully developed foetus and placenta send signals for parturition which in turn induces mild uterine contractions by stretching of cervix referred to as foetal ejection reflex. Stretching of cervix exerts positive feedback on the posterior pituitary to secrete oxytocin. Oxytocin exhibits both direct and indirect (via prostaglandins) effect on the uterus to facilitate uterine contractions to push the foetus downward which in turn stretches cervix more and leads to childbirth. Relaxin is secreted by corpus luteum at the end of pregnancy. It serves to relax the pelvic ligament and cervix to facilitate the birth of young one.