What is parturition? Which hormones are involved in induction of parturition?
Parturition is the process of delivery of the foetus (childbirth). It is caused by vigorous contraction of the uterus at the end of the pregnancy, leading to the expulsion of the baby out of the uterus through the birth canal.
The induction of parturition involves a complex neuroendocrine mechanism. The hormones involved in this process are cortisol, estrogens, and oxytocin. Signals from the fully developed foetus and placenta induce mild uterine contractions called the foetal ejection reflex. This triggers the release of oxytocin from the maternal pituitary, which acts on the uterine muscles to cause stronger contractions, resulting in the delivery of the child.
Explanation
The answer is derived from the provided text which defines parturition in the section '2.7 PARTURITION AND LACTATION'. The context explicitly lists cortisol, estrogens, and oxytocin as the hormones involved in the induction of parturition. It also describes the neuroendocrine pathway where the foetal ejection reflex stimulates oxytocin release to facilitate the delivery.
Solution Steps
Step 1: Define Parturition based on the text as the process of delivery of the foetus caused by uterine contractions.
Step 2: Identify the hormones listed in the text responsible for induction: cortisol, estrogens, and oxytocin.
Step 3: Briefly describe the mechanism mentioned (foetal ejection reflex triggering oxytocin) to ensure the 3-mark requirement is met comprehensively.