Assignment task: Olivia is just beginning her third trimester of pregnancy, and she made an appointment with her obstetrician to discuss some new symptoms she's experiencing. She has noticed increasing puf?ness in her feet, to the point that her old shoes no longer ?t. When she stands up after sitting or lying down, she feels a bit dizzy and faint. Even more concerning, Olivia noticed that she feels sweaty, nauseous, and particularly dizzy when she lies down on her back. Olivia tells the doctor she ?nds this frustrating, since she gets tired quickly and wants to be able to rest as much as possible. Olivia's doctor examines her and notes tachycardia and hypotension. She tells Olivia that the symptoms she's noticing are quite common in pregnant women and are sometimes diagnosed as supine hypotensive syndrome. The condition gets its name because these pregnant women experience hypotension when lying on their backs, or in a "supine" position. The doctor says that Olivia's baby and uterus are getting bigger, and the uterus can press down on one of Olivia's main blood vessels, called the inferior vena cava. The compression on this vessel creates the symptoms Olivia is experiencing. The doctor tells Olivia she will feel much better when she sleeps and rests if she lies down on her side, not on her back. That change in position will take much of the pressure off of her vena cava. Write your answer question by question.
Question 1: Explain how compression of Olivia's inferior vena cava changes the dynamics of capillary exchange, such that she experiences symptoms such as swollen feet.
Question 2: How do you think compression of Olivia's inferior vena cava will impact cardiac output, and why?
Question 3: What regulatory mechanisms in Olivia's body most likely contribute to the tachycardia the doctor noted?