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Meaning, manner, mechanism, cause and time

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Presentation on theme: "Meaning, manner, mechanism, cause and time"— Presentation transcript:

1 Meaning, manner, mechanism, cause and time
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 Accidental Suicidal
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

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: /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 Time Event Appearance 2-6 hours Rigor begins
eyelids, Jaws stiffen After 2 hours then center of body stiffens 12 hours Complete Rigor Entire body rigid 15-36 Slow loss of rigor, small muscles first Lost in head and neck, last is bigger leg muscles 36-48 Rigor disappears, muscles become relaxed

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

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 fluids 9. 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-

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