Assignment 3

1 .		How can we help a patient overcome problems due to hemorrhaging? In addition to the obvious and immediate treatment—stopping the blood loss—consider other treatments for a patient who is hemorrhaging.
2 .		Imagine that you are a nurse or a physician caring for a woman who has just delivered a child. Childbirth proceeded without complications and this woman is showing no outward signs of hemorrhaging. She is now sleeping comfortably. Although there are no outward signs of hemorrhaging, she is experiencing a small amount of (internal) bleeding from her uterus. Simulate this condition as follows: Click on the Interventions tab at the top of the screen. Notice that Small Hemorrhage appears in the popup menu as the default condition. Click Start to begin the simulation, allow this to proceed normally for several seconds, and then click on the Apply Intervention button to induce a small amount of bleeding. Carefully look for changes in each recording. Which parameters changed? Which remain unchanged? Explain these results.
3 .		Does blood pressure return to normal in this patient due to homeostasis? If so, explain which parameters changed to allow her blood pressure to return to normal.
4 .		A man is walking across the street in a busy city at rush hour and is accidentally struck by a delivery truck. Fortunately, a school crossing guard has noticed the accident and immediately calls for an ambulance. Upon arrival at the accident scene, the emergency medical personnel notice that this individual has been bleeding excessively from a wound to his leg. Simulate this condition as follows: Click on the Start button to begin the simulation. In the Interventions view, click on the popup menu and select Large Hemorrhage, then click on the Apply Intervention button. Notice the immediate decrease in blood volume. Note any other changes in cardiovascular parameters. How is this patient's cardiovascular system responding in an effort to achieve blood pressure homeostasis?
5 .		What is happening to heart rate? Does this make sense? Why or why not? What is happening to stroke volume? What is happening to total peripheral resistance? Explain each observation.
6 .		Do these responses return blood pressure to normal?
7 .		Assume that you have taken appropriate measures to stop the hemorrhaging. Help this patient by increasing his blood volume through a blood transfusion. To do this, click on the Variables tab. Click on the slider for blood volume and gradually increase blood volume while monitoring blood pressure and heart rate. Give this patient more blood until you have given him enough to return his blood pressure and heart rate to normal. Hold blood volume steady until blood pressure and heart rate have stabilized. What happened to other parameters of the cardiovascular system as you gave him more blood? Explain these changes.