Decomposition

definition of death

the cessation or end of life

what is a natural manner of death

failure of body functions due to old age or disease (most common)

what is a accidental manner of death

result of unplanned event (ex. car crash)

what is a suicidal manner of death

intentional killing of oneself

what is a homicidal manner of death

death caused by another individual; murder

what is a undetermined manner of death

MOD cannot be determined

what does the cause of death refer to

the underlying cause of death

ex) if someone is exposed to large amount of radiation then developed cancer, the proximate cause of death is exposure to radiation 

when figuring out the time of death what clued on the body do pathologists use

1. stomach

2. eyes

3. 4 postmortem stages

4. entomology

5. putrefaction & decomposition

6. Skeletonization

what are the 4 postmortem stages of death

1. pallor mortis

2. algor mortis

3. rigor mortis

4. livor mortis

what is pallor mortis

increased paleness die to cessation of blood circulation

15-30 min after death

what is algor mortis

loss of the bodies temp to match ambient temp

what is rigor mortis

death stiffness

this begins in the head after 2 hours ofter death then works its way down the body and legs

peaks at 12 hours

stiffness completely disappears after 36 hours

what is livor mortis

death color

indicates the bodies positioning of the body during the first 8 hours of death

how can stomach and intestinal contents help determine a TOD

• 4-6 hrs for the stomach to empty into the small intestines

• 12 hrs to leave the small intestines

• 24 hrs released from large intestines

how can changes in the eyes help determine the TOD

following the death the surface of the eyes dry out

a film will appear within 2-3hrs

when the eyes remain open and dry out fully a yellowish then brownish blackish band (seen 3-7 hrs after death and can disappear in a day or later)

definition of autoposie

(post mortem examination - highly specialized surgical procedure that consists of the examination of a corpse to determine cause and manner of death.

also to evaluate any disease or injury

what are some deaths that require an autopsy

• homicide

• children

• unusual deaths

• also can be requested by family

what are some deaths that do not require an autopsy

• elderly

• anyone with terminal illness

what are two types of autopsies

forensic/ medical-legal autopsy (help solve a crime)

clinical autopsy (determine cause of death) (research and or study purpose)

what is a coroner responsible for

• identifying body

• notifying the next if kin

• collecting and returning any personal belongings

• signing the death certificate

what are the 13 steps to an autopsy

1. body arrives to medical examiner (hospital bag or evidence sheet)

2. new bag for new body

3. bag is broken into and the body is photographed still in the bag

4. evidence is collected off the external surfaces

5. body is removed from bag and undressed, wounds are examined, body is weighed, and measured

6. note features —> race, sex, age, hair color and length, eye color, age, and any identifying features (scars, tattoos ect.)

7. bodily fluids and withdrawn from body

8. cut the Y-shaped incision (sholder-to-sholder meeting at breastbone all the way down to pubic bone)

9. peel back skin, exposing ribcage and neck muscles

10. cut the ribcage

11. organs are exposed, series of cuts made to detach organs

12. cut behind one ear across the forehead to the other ear and around. skull is cut with electric saw, exposing the brain

13. after all examination return organs, sew chest back together, put skull cap back on

what are the 5 steps of decomosition

1. fresh

2. bloat

3. active decay

4. advanced decay

5. dry remains

explain fresh decay

• 0-3 days

• livor, rigot, and algor mortis occur

explain bloat

• 4-10 days

• gasses rise to the bloated appearance

• strong odor

• skin turns greenish

• skin may break apart and fluids can flow out from openings

explain active decay

• 10-20 days

• great loss in mass (b/c of feedings by maggots and other insects)

• all gasses have escaped, bod may collapse

• end of this stage marked by dispersal of maggots from the body

explain advanced decay

• 20-50 days

• body begins to dry (most flesh is gone)

• odor and insect activity decreased

• body may form wax layer (adipocere)

explain dry remains

• 50 days - 1 yr

• recognizable by loss of everything on the body but dried bone

who decomposes faster then who

• young faster than old

• overweight faster than average

• naked faster than clothed

• sick faster than heathy

• fastest in 70-99 degrees F

what insects show up during fresh decay and what are they doing

blowflies

• only lay eggs on the corpse not eating the body

what insects show up during bloat and what are they doing

blowflies, flesh flies, and maggots (baby blowflies)

• both are only laying eggs not eating the body

what insects show up during active decay and what are they doing

blowflies, flesh flies, maggots, parasitic wasps

• wasps interested in blowflies flesh flies and maggots not in the body

what insects show up during advanced decay and what are they doing

blowflies, flesh flies, maggots, parasitic wasp, and rover beetles (and larva)

• everything is the same except the beetles are consuming the body and laying eggs

what insects show up during dry remains and what are they doing

parasitic wasp, moths, dermestid beetles (and larva), and mites

• beetles eat the dry flesh and laying eggs

• moths and mites are eating the body

how can larva help develop and determine the TOD

Because blowflies are first and development of the larva are useful when finding the TOD