If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Understand: feedback in living systems


During the process of childbirth in humans, the fetus moves down the birth canal and puts pressure on the cervix, a structure located at the bottom of the uterus. This sends signals to the brain to trigger release of oxytocin, a hormone that causes contractions. As the uterus contracts, it causes additional pressure on the cervix, which leads to further release of oxytocin. This continues until the baby is born.
Which statement best explains the type of feedback loop involved in childbirth?
Choose 1 answer: