Final answer:
Oxytocin stimulates uterine contractions during childbirth, facilitated by a positive feedback mechanism. Increased oxytocin receptor expression and prostaglandin release enhance contractile strength. Synthetic oxytocin, or pitocin, may be used to induce labor if necessary.
Step-by-step explanation:
The hormone oxytocin is key in the process of childbirth, where it stimulates uterine contractions necessary for labor and delivery. Oxytocin is a peptide-derived hormone secreted by the posterior pituitary gland and plays a pivotal role in the regulation of labor. Its release is prompted by the stretching of the cervix as the fetal head presses down, triggering a positive feedback mechanism that enhances the production and release of oxytocin, thereby increasing the intensity and frequency of uterine contractions. This continues until the baby is born and the stimulus for oxytocin secretion ceases. When labor is not progressing naturally, a synthetic version of oxytocin, known as pitocin, is sometimes administered to induce the labor process.
This hormone's effects are mediated through oxytocin receptors, which increase in number towards the end of pregnancy, making the uterus more sensitive to its effects. The placenta also contributes to labor induction by releasing prostaglandins that work synergistically with oxytocin to strengthen uterine contractions. The whole process is an exquisite example of hormonal regulation culminating in the birth of a human infant.