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The diagram shows the effect of the hormone oxytocin on the uterus during the birth of a mammal - HSC - SSCE Biology - Question 18 - 2019 - Paper 1
Question 18
The diagram shows the effect of the hormone oxytocin on the uterus during the birth of a mammal. 1. Uterine contractions force foetus against cervix stimulating mec... show full transcript
Worked Solution & Example Answer:The diagram shows the effect of the hormone oxytocin on the uterus during the birth of a mammal - HSC - SSCE Biology - Question 18 - 2019 - Paper 1
Step 1
Identify the feedback loop
Answer
The diagram illustrates a positive feedback loop. In a positive feedback loop, the output enhances or amplifies the changes occurring in the system. This is evident as the release of oxytocin leads to more intense uterine contractions, which in turn stimulates further release of oxytocin.
Step 2
Explain the feedback mechanism
Answer
During childbirth, the pressure of the fetus against the cervix stimulates nerve impulses that are sent to the brain. This triggers the hypothalamus to release oxytocin from the posterior pituitary gland, which in turn increases the frequency and strength of uterine contractions. As the contractions increase, more pressure is applied to the cervix, leading to further release of oxytocin, creating a cycle that continues until delivery.