Decomposition

Question 1

Describe somatic/body death

Answer 1

Cessation of cardiopulmonary function
Blood fails to flow to organ systems
Lack of oxygen
Whole systems fail

Question 2

Describe neurologic death.

Answer 2

Cessation of most neurological activity, cardiopulmonary function remains
Irrecoverable

Question 3

List three types of cellular death

Answer 3

Apoptosis
Necrosis
Autolytic

Question 4

What is apoptosis?

Answer 4

Preprogrammed cell death

Question 5

What is necrosis?

Answer 5

Cellular and tissue-level localized death due to pathology

Question 6

Describe autolytic cellular death

Answer 6

Enzymatic non-programmed self-destruction

Question 7

What are the two phases of decomposition?

Answer 7

Intrinsic and extrinsic

Question 8

What happens during the intrinsic phase of decomposition?

Answer 8

Cells - autolysis
Bacterial release

Question 9

What happens during the extrinsic phase of decomposition?

Answer 9

Soft tissue changes

Question 10

What is the extrinsic stage of decompositon used to determine?

Answer 10

PMI

Question 11

When does autolysis occur? Why?

Answer 11

Occurs when the cellular processes used to keep native enzymatic activity in check ceases.
Caused by lack of O2 and other material due to deprivation of active blood flow.

Question 12

Describe the 4 stages of the decompositional process.

Answer 12

Fresh
Early
Advanced
Skeletalization/Mummification

Question 13

What occurs during the fresh stage of decomposition?

Answer 13

Autolysis
Mortis triad

Question 14

What is the mortis triad?

Answer 14

Algor, Livor, Rigor

Question 15

What happens during early decompositon?

Answer 15

Bloating
Skin slippage
Purging

Question 16

What happens during advanced decomposition?

Answer 16

Compression/deflation
Initial skeletalization

Question 17

What happens during skeletalization/mummification?

Answer 17

Skeletal elements more than 75% exposed
OR skin becomes mummified

Question 18

What is livor mortis?

Answer 18

Pooling/settling of blood in the body.

Question 19

What is lividity?

Answer 19

Bluish-purple discoloration after death

Question 20

What is blanching?

Answer 20

Lividity not fixed.

Question 21

What is algor mortis?

Answer 21

Cooling or warming of the body to ambient temperatures

Question 22

What is the rate of algor mortis in climate controlled environments?

Answer 22

2 deg F/hr
~1.11 deg C/hr

Question 23

What is algor mortis used to help estimate?

Answer 23

PMI

Question 24

What factors affect algor mortis (3)?

Answer 24

Clothing
Pathology
Humidity

Question 25

What is rigor mortis?

Answer 25

Stiffing of the body postmortem

Question 26

What causes rigor mortis?

Answer 26

Adenosine triphosphate released from muscles due to contraction

Question 27

When does rigor mortis first appear?

Answer 27

30 mins to 2 hours after death

Question 28

When is rigor mortis completely fixed?

Answer 28

12 hours

Question 29

When does rigor mortis start relaxing?

Answer 29

24-36 hours postmortem

Question 30

What is the Megyesi scale? How does it work?

Answer 30

Scale used to measure decomposition Scores the head, trunk and limbs and then adds scores

Question 31

What stages are included in the Megyesi scale?

Answer 31

Fresh Early Advanced Skeletonization

Question 32

What is total body score used to calculate?

Answer 32

Degree of decomposition

Question 33

What is examined in the total body score?

Answer 33

Head and neck Torso Limbs (together)

Question 34

What is the lowest total body score? Highest?

Answer 34

Lowest = 3 for fresh in all three regions Highest = 35 for skeletonized

Question 35

Describe the charactersitcs of fresh decomposition.

Answer 35

Clean with no colouration changes Early stages with lividity present and fixed

Question 36

How is fresh decomposition assessed?

Answer 36

Across the body at 1 point

Question 37

Describe the characteristics of a body at early decomposition. (7)

Answer 37

Autolysis and early putrefaction Skin slippage Blistering Marbling Green to grey colouration Bloating Purging of fluids

Question 38

Where does autolysis and early putrefaction typically start?

Answer 38

In the ileocecal junction

Question 39

Describe the characteristics of a body at advanced decomposition.

Answer 39

Caving in of the flesh Moist decomposition with bone exposure at less than 1/2 of the body

Question 40

Describe the characteristics of a body at the skeletalization stage.

Answer 40

Most to all of the skeleton exposed Bones are generally greasy to dry Adipocere formation

Question 41

What is adipocere?

Answer 41

"Grave wax"

Question 42

In what conditions does adipocere occur?

Answer 42

Moist environments

Question 43

What is mummification?

Answer 43

Desiccation of tissues

Question 44

What usually causes mummification?

Answer 44

Aridity/lack of moisture in the air

Question 45

How might the environment tell us that a body is recently decease vs. longer deceased?

Answer 45

Recent - dead vegetation patch; abnormal mound Longer = more lush vegetation, abnormal depression

Question 46

How can taphonomy be affect by environment?

Answer 46

Acidic soil = dissolved bone Surface remains = sun bleached white

Question 47

Give examples of environmental conditions that can impact decomposition (8).

Answer 47

Temperature Burial depth Humidity/aridity Type of surface Accessibility of insects Carnivore and rodent activity Rainfall Soil pH

Question 48

Describe compositional research in 1965.

Answer 48

First decomp study, focused on insect succession on remains Found that pigs were analogous to humans with regards to insect activity only.

Question 49

Describe decomp research in the 1970s.

Answer 49

William Bass and his Colonel What was thought to be more recent remains turned out to have been 100 years old.

Question 50

Describe decomp research in the 70s/80s/

Answer 50

William Bass opens the UTK Anthropological Research Center in Knoxville, TN.

Question 51

Describe decomp research in 1994.

Answer 51

Daubert v. Merrell Dow Pharmaceuticals SC ruling changes forensic specific standards

Question 52

How can past decomp research be described as bad science?

Answer 52

Limited number of subjects Did not account for compounding variables (ex. height, weight, fat content, exsanguination status, etc.)

Question 53

What has recent research found about decomp studies on pigs?

Answer 53

Pigs are not analogous to humans.