Chapter 1 Discussion Forum

DUE: MONDAY, SEPTEMBER 23 AT 11AM EST

Mary was excited when she first felt regular contractions, signaling that she would soon meet her new baby. Few physiological activities in the human body are so outwardly awe-inspiring as the birth of a child, particularly for the child’s parents! Birth usually occurs vaginally in a process referred to as “labor.” Mary had read that during labor, her body would go through a number of changes to allow the baby to safely exit her uterus and vagina. She knew that labor would begin with the baby’s head stretching the exit to her uterus, called the cervix. Nerve cells in her body would sense this stretching and transmit the message to her brain. Her brain would then produce hormones to stimulate contractions in her uterus, which would further stretch her cervix. That process, which Mary knew had just started in her body, would continue until her cervix was stretched wide enough for her baby to exit.

While Mary hoped her child would be born vaginally, she also realized it wasn’t entirely unusual for childbirth to occur via a surgical procedure called a Caesarean section. This would involve a major surgery, but Mary realized it is sometimes necessary for the safety of a baby or a mother. In a Caesarean section, surgeons make a cut into the mother’s abdominopelvic cavity. The cut is typically along the transverse plane in the hypogastric region, superior to the inguen. Surgeons locate the uterus dorsal to the bladder and anterior to the rectum. Usually, the cut into the uterus is also along the transverse plane just superior to the edge of the bladder. The baby is delivered through that incision. Mary had done some research on this procedure while she was pregnant so that she would understand the various ways her childbirth might progress. For now, though, she tried to relax for what she knew would be a challenging, but ultimately very rewarding, process of labor.

Questions

1. Identify the components of the feedback loop involved in the process of labor. Would this example constitute negative or positive feedback, and why?

2. Diagram the surgical procedures discussed above (draw on a piece of paper, photograph and attach; or create a digital drawing and attach) for a Caesarean section. In your diagram, indicate the locations of the cuts made and describe the relative locations of the uterus, bladder, and rectum.

3. Given the location of a Caesarean section surgery, what are the names and characteristics of the membranes you think surgeons must cut through in order to view the uterus?