AIIMS 2010
- Exam
- AIIMS
- Year
- 2010
- Subject
- Zoology
- Chapter
- Human Reproduction
AIIMS 2010 · Zoology · Human Reproduction
Assertion : Parturition is induced by neural signal in maternal...
Assertion : Parturition is induced by neural signal in maternal pituitary.
Reason : At the end of gestation period, the maternal pituitary release prolactin which causes uterine contractions.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
D. If both assertion and reason are false.
Step-by-step solution
The process of delivery of the foetus (childbirth) is called parturition. Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex. This triggers release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle 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 expulsion of the baby out of the uterus through the birth canal.