BSN 346 Week 2 Hormonal Changes Test Questions and Answers

Hormonal Changes - Answer-Labor begins when forces favoring continuation of pregnancy are overcome by forces favoring its end. The exact mechanisms that cause the beginning of labor are not fully understood by scientists. However, there is a very clear hormonal shift that is observed (Perry et al., 2018). Estrogen and Progesterone - Answer-Rising estrogen levels counteract the action of progesterone. When estrogen levels rise above progesterone levels, the relaxant effects of progesterone on the uterine muscle are reduced. This enables uterine contractions to begin. Prostaglandins - Answer-Prostaglandins are secreted from the lower area of the fetal membranes (forebag) during labor, which prepares the uterus for oxytocin stimulation. Oxytocin - Answer-The natural increase in secretion of oxytocin from the mother and the increase in oxytocin availability resulting from the compression of the fetal head on the cervix progress and maintain labor once it has begun. Oxytocin receptors in the uterus increase markedly during labor and peak at delivery, allowing oxytocin to have its effect on the uterus. Fetal Role - Answer-The fetal membranes release prostaglandin in high concentrations during labor. In addition to fetal oxytocin secretion, large quantities of cortisol are secreted by the fetal adrenal gland, possibly acting as a uterine stimulant. Uterine and Cervical Feedback Loop - Answer-A feedback loop is probably responsible for labor contractions at term: the fetal head stretches the cervix, causing the fundus of the uterus to contract, pushing the fetal head against the cervix, thus causing more pressure, which triggers more fundal contractions. In addition, cervical stretching causes secretion of oxytocin