Decomposition Flashcards
(47 cards)
What is decomposition?
Decaying caused by bacteria or fungal action
A continual process that can take weeks to years, depending on the environment and is necessary for all life on earth.
What is taphonomy?
Study of burial and everything surrounding it
It involves the transition of living organisms from the biosphere to the lithosphere.
What is a necrobiome?
The microbiome of bacteria present in the body after death
It becomes influenced by its environment and also influences its environment.
What is the significance of vegetation in decomposition?
Differential plant growth can be visible for years, aiding in the identification of mass graves
Some species, like wormwood in the Balkans, can serve as markers.
What does forensic taphonomy study?
The fate of human remains in relation to criminal law
It includes PMI estimation, timelines of events, and the investigation of cadavers.
What are the traditional stages of decomposition?
- Fresh
- Bloat
- Active decay
- Advanced decay
- Skeletonisation
Research may propose different categorizations.
What regulates decomposition?
Resource quality, decomposer community, and physiochemical environment
Factors include body mass, temperature, and oxygen levels.
What is autolysis?
The breakdown of cells within the body due to self-digestion
It is followed by putrefaction and is a primary driver of decomposition.
What is PMI estimation?
Time since death estimation
It relies on evidence from the body, environment, and daily activities.
Why is PMI important?
It impacts legal questions regarding alibi, opportunity, and cause of death
It helps implicate or eliminate suspects.
What are the two types of PMI estimation methods?
- Rate method
- Occurrence method
The rate method is generally considered more reliable.
What is rigor mortis?
The stiffening of muscles after death
It begins within 3-6 hours of death and resolves within 36 hours.
What is livor mortis?
The pooling of blood due to gravity after death
It typically appears within 30 minutes to 1 hour after death.
What does the fresh stage of decomposition involve?
Paling of skin, relaxation of muscles, and changes in body temperature
Autolysis is the primary driver during this stage.
What occurs during the bloat stage?
Gas buildup causes distension, leading to greenish discoloration
This stage is driven by bacterial action.
What characterizes the active decay stage?
Maggots hatch and destroy the integrity of the body
Bacterial action continues, and gases are released.
What happens during advanced decay?
Drying out of remains and retreat of maggots
Insect activity shifts from maggots to beetles.
What is skeletonisation?
The gradual exposure of bones as decomposition slows down
It becomes harder to estimate PMI at this stage.
What are extrinsic factors that affect decomposition?
- Temperature
- Access by insects
- Moisture/humidity
- Sun/shade
- Burial environment
Each factor influences the rate and process of decomposition.
What are intrinsic factors affecting decomposition?
- Body size
- Surface area to volume ratio
- Fat content
These factors influence how quickly a body decomposes.
What is cadaveric spasm?
Immediate muscle stiffening in response to high tension
It differs from rigor mortis and can occur in situations like drowning or violent homicide.
What is the role of scavengers in decomposition?
They contribute to mechanical breakdown of remains
Different populations of scavengers exist based on geographical location.
What is desiccation in the context of decomposition?
Browning of the skin due to drying exposure to heat or air
It leads to differential decomposition rates.
What is desiccation in the context of decomposition?
Browning of the skin/membrane due to drying/exposure to heat or air
