When Did She Die Activity

When Did She Die Activity - When Did She Die Directions...

This preview shows page 0 - 1 out of 4 pages.

Info icon Subscribe to view the full document.

Unformatted text preview: When Did She Die? Directions: Read the passage. Work with a partner to answer the data analysis questions and make the graph. Each student must complete his or her own data sheet and graph. The Problem: Your medical examiner team has been given the following case to review. It is your job to determine whether the victim died accidentally and what the time of death was. Study the details and complete the data analysis report that follows. Medical Examiner’s Report: The victim was found in her home at 10:00 A.M. on a Saturday morning by her sister with whom she was supposed to go jogging. The sister promptly called the police who then notified you, the medical examiner. You noted the following: • The victim was lying facedown at the bottom of the stairs, facing away from the stairs. The sister indicated the victim was dressed in the clothes she had worn to dinner the night before. • The victim had no pulse. • The body was cold to the touch, but the internal temperature, which was measured at 10:30 A.M. was 27ºC (room temperature was 20ºC). • Her neck was apparently fractured and she appeared to have sustained head injuries. • There were purplish marks on the front of her shoulders and neck. The marks did not change color when touched. • Her entire body was stiff. • The victim’s eyes were open and cloudy with a thin film. Additional Police Notes: Witnesses saw the victim eating an early dinner with her sister at 4:00 P.M. the night before (Friday evening). At dinner they had agreed to meet at the victim’s town house at 10:00 A.M. Saturday morning to go jogging. The sister stated she dropped the victim off at her house at 11:00 P.M. and returned to her own home at 11:15 P.M. Neighbors did not recall seeing the victim return to the town house. When you performed an autopsy on the victim later that day, you noted that she died of a broken neck and subsequent asphyxiation. The victim was 5 feet 8 inches tall and weighed 130 pounds. Her stomach was empty, and her small intestine was full. Your job is to provide police with the time of death and whether or not you believe the death was accidental. Name: ___________________________________________ Date: _______________ Per: ____ When Did She Die? Data Analysis Report 1. What is the normal body temperature in ºC? ____________________________________ 2. What biological process allows humans, other mammals, and birds to maintain high body temperatures? ____________________________________________________________ 3. Research and explain briefly the role of ATP in muscle contraction. _________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 4. Explain the path that food takes through the digestive system in your body. ___________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 5. Based on the background information about the average body temperature decrease after death, calculate the body temperature for each hour up to 24 hours after death. Don’t forget that the average decrease changes after 12 hours! Hour 1 2 3 4 5 6 7 8 Body Temp ºC Hour 9 10 11 12 13 14 15 16 Body Temp ºC Hour 17 18 19 20 21 22 23 24 Body Temp ºC 6. Plot the data for temperature versus time after death on graph paper. Turn the paper sideways so you have a longer X axis. Time goes on the X axis. Remember to title the graph and label the axes. Use pencil. 7. Based on the body temperature of the victim, how long has it been since the victim died? ________________________________________________________________________ 8. Estimate the time of death using body temperature. ______________________________ 9. Based on the observation of rigor mortis, how long has the victim been dead? _________ 10. Where was lividity observed on the body? _____________________________________ 11. Was the lividity fixed? _____________________________________________________ 12. How long ago did she die based on lividity? ____________________________________ 13. Was the victim found in the position that she died or was she moved? Explain your answer._________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 14. Based on the appearance of her eyes, how long ago did she die? Explain your answer. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 15. Based on the examination of her digestive system, how long after a meal did the victim die? Explain your answer. __________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 16. Based on ALL of the evidence available, estimate the time of death for the victim and explain how you arrived at that time. __________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ 17. Is it your opinion that the victim’s death was an accident? Explain how you arrived at your answer and write a brief story of what you think happened last night. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ BACKGROUND When a body is discovered, one of the first things that a medial examiner must do is determine the time of death. The medical examiner uses several indicators to help establish the time of death, including body temperature, rigor mortis, discoloration (livor mortis or lividity), and the appearance of the eyes. BODY TEMPERATURE Average body temperature for a person is 98.6ºF, or 37ºC. When a person dies, the body immediately begins to cool. On average, the body temperature drops at a rate of 0.75ºC per hour for the first 12 hours. After 12 hours, the rate of cooling slows by about one half to approximately 0.4ºC per hour, until the body reaches ambient temperature, the temperature of the environment. The rate of cooling is also affected by the following factors: Air temperature – a body will cool faster on a cold winter night than on a warm summer night. Body fat – Fat tends to insulate the body so the more fat a person has, the slower the body cools after death. Clothing – Clothing also insulates the body, so heavy clothing will slow the rate of cooling. Water – A body in water cools much faster than one in air. Therefore, it is difficult to use body temperature to estimate the time of death for a victim found in the water. RIGOR MORTIS At the time of death, the body’s muscles are relaxed. However, within 1-2 hours, the muscles begin to stiffen as their stores of adenosine triphosphate (ATP) become exhausted. This stiffening is known as rigor mortis. Rigor mortis begins with the muscles of the face, jaws, and neck, proceeds down the body through the upper arms and torso, and ends with the legs. This process is complete within 8-12 hours after death. As the muscles begin to break down, they relax in the same order as they stiffened. By 2448 hours after death, the body is totally relaxed again. LIVOR MORTIS (LIVIDITY) Within 1-2 hours after death, the blood settles into the lowest parts of the body (parts that are closer to or resting on the ground) due to gravity. The red blood cells settle out and break down into the tissues, leaving purplish marks that later become yellow (due to the break down of hemoglobin). This color (lividity) becomes fixed in the tissue within 6-8 hours after death. If a body is moved after this time, then the position of the purplish marks may not agree with the position in which the body is found. Finally, if skin appears discolored, but turns white when touched, then lividity has not been fixed and death probably occurred more than 2 hours, but less than 10 hours ago. APPEARANCE OF THE EYES If the eyes remain open at the time of death, then a thin film will appear on them as they begin to dry out. As the blood cells within the body break down, they release potassium. Potassium enters the eyes and causes them to appear cloudy. This process takes approximately 2-3 hours after death; however, if the eyes remain closed after death, then the process takes much longer (approximately 24 hours). STOMACH CONTENTS After you eat, the process of digestion takes place. Digestion begins in the stomach. It takes about 4-6 hours for the stomach to empty its contents into the small intestine. Finally, it takes approximately 12 hours for the food to leave the small intestine. As a rule of thumb: • Undigested stomach contents-death occurred 0-2 hours after the meal. • Stomach empty-death occurred 4-6 hours after the meal. • Small intestines empty-death occurred 12 hours or more after the meal. ...
View Full Document

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern