Zoology - Human Reproduction Question with Solution | TestHub

Parturition is induced by a complex neuroendocrine mechanism which is triggered by the fully formed foetus and the placenta called foetal ejection complex. This encompasses the mild uterine contractions in response to the trigger. A developing foetus secretes hormones from its adrenal glands. These hormones diffuse into the maternal blood and accumulate to stimulate the release of oxytocin (birth hormone) from the mother’s posterior pituitary. Oxytocin acts on the uterine muscle and causes stronger contractions, which in turn stimulates the further secretion. The stimulatory reflex between the uterine contraction and oxytocin secretion continues resulting in stronger and stronger contractions leading to the expulsion of the baby out of the uterus through the birth canal.