Question

Why is positive feedback helpful when a woman is in labor, but not when it comes to regulating temperature change in the human body? What role does negative feedback play in labor?

Answer 1

Positive feedback mechanisms are rare cases. It amplifies changes rather than reversing them. The release of oxytocin from the posterior pituitary gland during labor is an suitable example of positive feedback mechanism. Oxytocin stimulates the muscle contractions that push the baby through the birth canal. The release of oxytocin result in stronger or augmented contractions during labor. The contractions intensify and increase until the baby is outside the birth canal. When the stimulus to the pressure receptors ends, oxytocin production stops and labor contractions cease.

With negative feedback, the output reduces the original effect of the stimulus. For example when body temperature is too high negative feedback will act to bring it to the normal condition.