Final answer:
The cervix and uterus widen to allow the birth of the fetus, with the cervix dilating to about 10 cm during the first stage of labor. The baby is expelled during the second stage, and the final stage involves the passage of the placenta. Pitocin may be used if labor stalls.
Step-by-step explanation:
The cervix and uterus widen from less than 1 cm to approximately 10 cm, allowing the birth of the fetus. During the first stage of labor, the cervix thins and dilates. This is necessary for the baby and placenta to be expelled during birth. By the end of this stage, the cervix will have dilated to about 10 cm. During the second stage, the baby is expelled as the uterus contracts and the mother pushes, utilizing her abdominal muscles to aid in the delivery process. The final stage involves the passage of the placenta after the baby has been born and the organ is completely detached from the uterine wall.
If labor should stop before the second stage is reached, a synthetic hormone called Pitocin, which is a form of oxytocin, may be administered to restart and maintain the labor process.