Class 12th Biology 2015 Set1 Delhi Board Paper Solution
Question 12
Describe the process of Parturition in humans.
Answer
At the end of an average 9 months of gestation, vigorous uterine contractions lead to the delivery of the foetus. This process is called parturition.
Parturition is a neuroendocrine mechanism and is started by the signals from the fully developed foetus and the placenta, which produce the foetal ejection reflex.
This causes release of oxytocin from posterior pituitary, which in turn causes even stronger uterine contractions. Contraction of uterine muscles leads to the expulsion of the baby along with the placenta, and hence completes the process of parturition.
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