(i) Signals originate from the fully developed foetus and placenta.
(ii) Induce mild uterine contractions (foetal ejection reflex).
(iii) Triggers release of oxytocin (from maternal pituitary).
(iv) Oxytocin acts on uterine muscles and causes stronger uterine contractions.
(v) Stimulatory reflex between the uterine contraction and oxytocin secretion continues resulting in stronger and stronger contraction.
(vi) Expel the baby from the **.
Detailed Answer:
- Parturition is the process of giving birth to a baby.
- The physical activities like uterine and abdominal contractions, dilation of cervix for passage of baby are involved in this process which are collectively called as labour and the discomfort or agony caused by it in known as labour pains.
- Parturition is controlled by a complex neuroendocrine mechanism
- Signals originate from fully formed foetus and placenta which induce mild uterine contractions called foetal ejection reflex. This causes the release of oxytocin from maternal pituitary.
- Oxytocin causes stronger uterine muscle contraction which in turn stimulate further secretion of Oxytocin. This Process is continued leading ultimately to expulsion of baby out of the ** through the birth canal.
- After parturition, the umbilical cord is tied and cut the placenta separated from *** and is expelled out due to series of strong uterine contractions.
