What is meant by parturition? Describe the changes occurring in the uterus during this period.

(N/A) The average duration of human pregnancy is about $9$ months,which is called the gestation period.
Vigorous contraction of the uterus at the end of pregnancy causes the expulsion or delivery of the foetus. This process of delivery of the foetus is called parturition.
Parturition is induced by a complex neuroendocrine mechanism.
The signals for parturition originate from the fully developed foetus and placenta,which induce mild uterine contractions called the foetal ejection reflex.
This triggers the release of oxytocin from the maternal pituitary gland.
Oxytocin acts on the uterine muscles and causes stronger uterine contractions,which in turn stimulates further secretion of oxytocin.
The stimulatory reflex between the uterine contraction and oxytocin secretion continues,resulting in stronger and stronger contractions.
This leads to the expulsion of the baby out of the uterus through the birth canal,known as parturition. Soon after the infant is delivered,the placenta is also expelled out of the uterus.