Death

1. Death Meaning, manner, mechanism, cause and time

2. Death • Meaning • Manner • Mechanism • Cause • Time

3. How do we define Death? • Is a person with a heartbeat alive even if there is no brain activity? • Death is a process not an event • Physiologists; when the heart stops beating, the cells begin to die • O2 levels drop • Basic processes of the body fails • Nerves, muscles, organs stop working, Stoppage • Once enough cellular death occurs life cannot restart

4. Forensic Pathologist • Examination of the deceased, Autopsy • Necropsy • Investigations normally are called upon when the death is: • Sudden • violent • unexplained deaths • Will Investigate • Manner • Cause • And mechanism of death • of Usually preformed by a coroner/medical examiner • Questions sought to answer: • Who is the victim • What injuries are present • When did the injuries occur • Why and how were the injuries produced

5. Forensic Pathology • Autopsy performed to establish cause of death. • Classifications the manner of Death • *Natural • *Homicide • *Suicide • *Accident • *Undetermined

6. Manner of Death • Five ways people die • Natural • Interruption and failure of bodily function resulting from age or disease • Accidental • Unplanned event • Suicidal • A person purposely kills oneself • Homicidal • Death of one person caused by another • Undetermined • Suicidal or accidental • Pills, guns

7. Do Now: Identify what is the Manner of Death? • Case 1: A man with a heart condition is attacked and dies from a heart attack during the assault. • Case 2: An elderly woman dies after being kept from receiving proper health care by her son.

8. Types of Death??? • Manner of Death, • Natural, Accidental, Suicidal, Homicidal, Undetermined • Cause of death:The reason someone dies • Disease: physical injury, stroke, heart attack • bludgeoning, shooting, hanging suffocation, • Mechanism of Death: the specific change in the body that brought about the cessation of life • exsanguinations (Blood loss) • Pulmonary arrest (Heart stoppage)

9. Cause and Mechanism of Death • Cause of death: The reason someone dies • Disease: physical injury, stroke, heart attack • Homicidal: bludgeoning, shooting, hanging suffocation, • Mechanism of Death: the specific change in the body that brought about the cessation of life • exsanguinations (Blood loss) • Pulmonary arrest (Heart stoppage)

10. Please provide the Manner, Cause and Mechanism of Death for John Locke. Remember the season finale, he was hung. • Manner of Death • Cause of death • Mechanism of Death

11. Please provide the Manner, Cause and Mechanism of Death for John Locke. • Manner of Death: Homicide • Cause of death:hanging suffocation, (asphyxia) • Mechanism of Death: hypoxia, • reduction of oxygen supply to a tissue

12. Time of Death • Livor Mortis • Rigor Mortis • Algo Mortis

13. Homework:Research and Identify How investigators estimate time of death..There are about 9 ways

14. Estimating Time of Death 9 Ways of Estimating Actual Time of Death: • Rigor mortis • Livor mortis: (Lividity) • Algor mortis: Body Core Temperature • Potassium levels in vitreous humor + Clouding of the cornea • Stomach Contents • Evidence of Decompositional Process • Presence/absence of purge fluids • Drying of the tissue • Insect Larval Instars http://www.dundee.ac.uk/forensicmedicine/llb/timedeath.htm#Time%20of%20Death

15. Algor Mortis 1. Algor mortis

16. 1. Algor mortis (L: algor—coolness; ath) • the reduction in body temperature following death. • a steady decline until matching ambient temperature • A measured rectal temperature can give some indication of the time of death. • Newton's law of cooling states that the rate of cooling of a body is determined by the difference between the temperature of the body and that of its environment. • The Glaister equation: 1-1 1/2 degree F per hour • Algor mortis is usually the first sign of death, beyond the obvious, and is then followed by rigor mortis. As decomposition occurs the internal body temperature tends to rise again. WHY?????

17. Questions: What are some Factors that would affect Algor Mortis? • Ambient temperature • Wind? • Excess body fat? • Clothing • etc

18. 2. Rigor Mortis • (L: rig- stiff; mortis—death) • Muscles become rigid • Starts w/I 2 hours but gone after 48 hours • After 48 hours muscles begin to autolysis (dissolve) • “The biochemical cause of rigor mortis is hydrolysis of ATP in the muscle tissue, the chemical energy source required for movement. Myosin molecules devoid of ATP become permanently adherent to actin filaments and muscles become rigid.”

19. 2. Rigor Mortis

20. 2. What are some factors affecting Rigor mortis ? • Ambient temperature, • Cooler the body the slower to onset of rigor • Person’s weight • fat stores more oxygen and slow rigor • Type of clothing • Helps keep the body warm • Illness • Dies with a fever? What would you expect? • Hypothermic? What would you expect? • Level of physical activity • Struggling before death rigor, What would you expect? • Sun exposure, • Sun tanner? What would you expect?

21. Live muscles fiber slide back and forth; in 48 hours after death, the muscles become locked in a fixed position

22. 3. Livor mortis or (postmortem lividity) L: liv-bluish) * Is a settling of the blood in the lower portion of the body ** Causing a purplish red discoloration of the skin. *** Discoloration does not occur in the areas of the body that are in contact with the ground or another object,

23. 3. Livor mortis

24. Special thanks to • http://classjump.com/dizengoff/documents/6929652646.pdf

25. 4. Rate of Decay

26. 4. Rate of Decay

27. 5. Stomach Contents

28. 6. Entomology

29. 6. Entimology

30. Blow Fly Life cycle

31. Total time 16 to 35

32. 6. Entomology Flies

33. Total time 16 to 35

34. 6. Entomology Beetles The American carrion beetle, Necrophila americana.  Although this beetle is primarily nocturnal, it is commonly observed on the upper surfaces of a body during the daylight hours.  Large aggregations of these beetles have been observed, and they can sometimes be as numerous as flies.  The sexton beetle,Nicrophorus orbicollis.  The sexton beetles are generally nocturnal and are typically found under a body or in the soil immediately surrounding the remains during the daylight hours. 

35. 7. Potassium levels in Vitreous humor and clouding cornea

36. 8. Presence/absence of purge fluids9. Drying of the tissue

37. Stages of Decomposition • Initial decay • Corpse appears normal, internal bacterial decay and autolysis begins • Putrefaction • Odor of decaying corpse swollen • Black Putrefaction • Very strong odor, flesh appears black, gases escape, corpse collapses • Dry Decay • Corpse is almost dry, further decay slows from lack of moisture

38. Guess the Stage of Decomposition

39. Stages of Decomposition • 2 days • Cells autolysis • Greenish purple staining occurs, blood decomposing • Skin takes on Marbled Appearance • 4 days • Skin blisters • Abdomen swells with carbon dioxide • Due to bacteria in intestines • 6-10 days • Corpse bloats with CO2 • Corpse eventually bursts • Fluid begins leaking from openings as cell membranes rupture • Eyeballs liquefy • Skin sloughs off

40. The-