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Questions and Answers
What occurs immediately after the heart stops beating?
What occurs immediately after the heart stops beating?
What is the first process that contributes to decomposition after death?
What is the first process that contributes to decomposition after death?
Under what circumstances is an autopsy generally mandated by state law?
Under what circumstances is an autopsy generally mandated by state law?
What characterizes putrefaction during the decomposition process?
What characterizes putrefaction during the decomposition process?
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What is the Postmortem Time Interval (PMI)?
What is the Postmortem Time Interval (PMI)?
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How much does the average body temperature drop per hour after death?
How much does the average body temperature drop per hour after death?
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How soon after death does livor mortis begin to show?
How soon after death does livor mortis begin to show?
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What is primary flaccidity in the context of rigor mortis?
What is primary flaccidity in the context of rigor mortis?
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What indicates that livor mortis has become fixed?
What indicates that livor mortis has become fixed?
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Which factors can affect algor mortis?
Which factors can affect algor mortis?
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What is the primary characteristic of the fresh stage of decomposition?
What is the primary characteristic of the fresh stage of decomposition?
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During which stage of decomposition does rigor mortis occur?
During which stage of decomposition does rigor mortis occur?
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How does the cornea change after death?
How does the cornea change after death?
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If undigested food is found in the stomach, what does it indicate about the time of death?
If undigested food is found in the stomach, what does it indicate about the time of death?
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What happens to the pupils immediately after death?
What happens to the pupils immediately after death?
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Decomposition is a natural process that begins with the breakdown of tissues after death.
Decomposition is a natural process that begins with the breakdown of tissues after death.
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Autolysis and putrefaction are two unrelated processes that do not occur simultaneously after death.
Autolysis and putrefaction are two unrelated processes that do not occur simultaneously after death.
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Doctors have up to 15 hours to harvest organs from a body after death occurs.
Doctors have up to 15 hours to harvest organs from a body after death occurs.
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The brain can survive for up to 10 minutes without oxygen before it dies.
The brain can survive for up to 10 minutes without oxygen before it dies.
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Attended deaths always result in a mandatory autopsy.
Attended deaths always result in a mandatory autopsy.
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The dry decay stage lasts from days 20 to 50 after death.
The dry decay stage lasts from days 20 to 50 after death.
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Clouding of the corneas happens within 3 hours if the eyes are open at the time of death.
Clouding of the corneas happens within 3 hours if the eyes are open at the time of death.
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Livor mortis begins to show immediately after death and becomes fixed after several hours.
Livor mortis begins to show immediately after death and becomes fixed after several hours.
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Potassium levels in the eye decrease after death, providing an unreliable time of death.
Potassium levels in the eye decrease after death, providing an unreliable time of death.
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During the bloated stage, the body is usually unrecognizable within 48 hours after death.
During the bloated stage, the body is usually unrecognizable within 48 hours after death.
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Livor mortis is the process where blood settles in the upper part of the body after death.
Livor mortis is the process where blood settles in the upper part of the body after death.
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Algor mortis causes the body temperature to increase after death until it matches the environmental temperature.
Algor mortis causes the body temperature to increase after death until it matches the environmental temperature.
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Rigor mortis begins approximately between 1-4 hours after death, starting in the jaw and neck.
Rigor mortis begins approximately between 1-4 hours after death, starting in the jaw and neck.
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If a body shows fixed livor mortis, it indicates that the body has not been moved for more than 8 hours after death.
If a body shows fixed livor mortis, it indicates that the body has not been moved for more than 8 hours after death.
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What occurs to the body cells shortly after the heart stops beating?
What occurs to the body cells shortly after the heart stops beating?
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Define autolysis in the context of decomposition.
Define autolysis in the context of decomposition.
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What is the purpose of an autopsy, and when might it be required?
What is the purpose of an autopsy, and when might it be required?
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How does the decomposition process differ in attended vs. unattended deaths?
How does the decomposition process differ in attended vs. unattended deaths?
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What are the key indicators of putrefaction during the decomposition process?
What are the key indicators of putrefaction during the decomposition process?
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Study Notes
The Process of Death
- Death is a process, not a single event.
- Processes occur from seconds to hours after death.
- Heart stops beating.
- Breathing ceases.
- Oxygen is no longer circulated.
- Brain dies within 3-7 minutes without oxygen.
- This is nearly always irreversible.
- Other cells and organs begin to die off.
- Doctors have up to 15 hours to harvest organs.
- Muscles relax.
- Bladder and bowels release.
Decomposition
- A natural process of tissue breakdown after death.
- The circulatory system shuts down, and tissue components leak out.
- Hydrolytic enzymes break down molecules.
- Bacteria break down the body from the inside out.
- Two parallel decomposition processes are; autolysis and putrefaction.
- Autolysis is the self-dissolution by body enzymes.
- Putrefaction is decomposition by bacteria and other microorganisms.
- Signs of this process include a change in color, bloating, skin slippage, and a strong odor.
Attended Deaths
- If death occurs in a hospital or hospice, a physician signs a medical certificate which notes cause of death.
- Autopsies may be performed if the cause of death is unknown or mandated by law.
- Families can request autopsies.
- Children under the age of 7 often require an autopsy.
- After autopsy, the body is returned to the family.
- The body is embalmed or cremated.
- Decomposition does not occur.
Unattended Deaths
- Unexpected or unassisted deaths require police investigation.
- Police treat unattended deaths as potential homicides.
- If bodies are found after days, months or years, it is a potential homicide investigation.
- Postmortem time interval (PMI) is the period between death and discovery of the body.
- Investigators study decomposition stages to determine the PMI.
- By narrowing down a timeline, investigators can find suspects.
Stages of Decomposition
- There are five stages of decomposition.
- Fresh (Days 0-3).
- Bloated (Days 4-10).
- Active Decay (Days 10-20).
- Advanced Decay (Days 20-50).
- Dry Decay (Days after 50).
Fresh Stage
- Decay begins immediately after death.
- Lasting approximately 3 days.
- The variability is based on the environment.
- Process characteristics are pallor mortis, clouding of the corneas, rigor mortis, and other signs (e.g. body with lighter skin becomes pale after death, it occurs within 30 minutes, clouding of corneas, liver mortis, rigor mortis (primary and secondary flaccidity), face unrecognizable after 24 hours).
Changes in Eyes
- The pupil dilates after death due to muscle relaxation.
- During rigor mortis, the pupils constrict.
- The cornea becomes cloudy and opaque.
- This happens usually within 2 hours if the eyes are open, within 24 hours if the eyes are closed (Tache noire forms within 3 hours after death, dark, red-brown stripe that develops horizontally across the eyes due to drying).
- Forensic scientists use potassium levels in the eye to estimate death time (Potassium levels increase after death without being affected by temperature).
Stomach Contents
- The digestive system stops digesting food after death.
- Food location in the tract helps determine time of death more accurately.
- This only works if someone ate recently before death.
- Food flows from stomach to small to large intestine.
- Undigested food in the stomach suggests death 0-2 hours after the meal.
- Undigested food in the small intestine, but not the stomach suggests death 4-6 hours after the meal.
- Undigested food in the large intestine but not the small suggests death 12+ hours after the meal.
Livor Mortis
- Blood settles in body's lower parts due to gravity.
- The skin turns red/purple.
- Livor mortis begins 20-30 minutes after death, noticeable after 2 hours.
- Fixed by 8 hours and doesn't change after that.
- Blanching (pressing of the thumb to check if livor mortis is fixed is valuable for investigation; determines 8 hours or later if body has been moved).
Algor Mortis
- Body temperature changes after death until it matches the environment.
- The body cools approximately 1.5°F per hour.
- The formula: 98.4 - rectal temperature = hours since death
- Factors affecting cooling include clothing, environment, drugs, health conditions, and the body's mass (fluctuation of environmental temperature, clothing worn, surface the body is on, drugs/disease which raise body temp before death, different rates for females versus infants, children, and seniors).
Rigor Mortis
- Muscles stiffen due to chemical changes.
- The primary stage is where the body becomes relaxed, precedes rigor mortis.
- Rigor mortis typically begins in the jaw and neck and spreads to the rest of the body by approximately 8 hours.
- Then the secondary stage is where the body becomes limp, starting with the jaw about 24 hours after death.
- The body is limp by 30-32 hours after death, and the entire body is limp by 36 hours after death and is in the bloat stage.
Bloated Stage
- Bacteria and microorganisms digest body tissues.
- Body and limbs bloat as gas is excreted.
- Foul-smelling chemicals (Putrescine and Cadaverine) are produced and the abdomen is the first part of the body to turn colors, typically green, blue, or red
- Skin slippage (degloving) and marbling can occur.
- Decomposition fluids affect the surrounding soil and vegetation, creating a "cadaver decomposition island".
Active Decay
- Accelerated putrefaction following bloating occurs (approximately 10-20 days).
- Body fluids liquefy and the skin darkens.
- Cadaver Island formation.
- Decomposition fluids disturb the soil and vegetation.
- Maggots actively break down body, then migrate to pupate.
Advanced & Dry Decay
- End of putrefaction, body appearance bursts (approximately 20-50 days).
- Bones, cartilage, hair, skin remain.
- Remains dry and animals feed on the hair.
- Only skeleton remains.
Rule of Decomposition
- One week in the air equals two weeks in water and eight weeks in soil.
Factors Impacting Decomposition
- Speeding factors; high humidity, temperature, and higher oxygen levels.
- Slowing factors; colder temperatures, larger body mass and higher fat levels, being in water or buried underground.
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Description
Explore the intricate process of death and decomposition in this informative quiz. Understand the stages that occur immediately after death, including physiological changes and the roles of autolysis and putrefaction. This quiz is essential for anyone interested in biology, medical science, or the natural processes of life and death.
