WARM UP #3 3/30 Settling of blood after death Stiffening of muscles after death Drop in temp after death What causes our body to become stiff? Why does blood settle after death?

Ch 3 NOTES #2 TIME OF DEATH PART 2 3/30

PUTREFACTION – AKA decomposition destruction of body tissue after death Due to enzymes and bacteria breaking down tissues in the body Studying amount of decay can give approx time of death SIGNS: odor, color changes, bloating

What happens to the body after decomposition starts? Within 24 hours: Decomp 1st starts in the abdomen– greenish in color Insects land on and feed on body

Bacteria inside produces gas, body swells (after 3 days body will float if in water) Insides continue to break down and turn into liquid Blood-stained fluid comes from nose and mouth (from gas pressure)

About 3-7 days: * Skin slip – epidermis detaches from dermis About 10-20 days: Skin rips open Body color darkens

Body Farm

Mummification (under right conditions) Skin hardens, turns leathery Hair and toenails can detach

GRAVE WAX – AKA adipocere fat from the body can remain after decomposition

Skeletonization Only bones left - can last centuries Can take a few weeks – several years

Rate of decomposition depends on Weather Wounds Body size 4. Insects 5. Oxygen (decomp in air faster than soil) 6. Wetness

DECOMPOSTION

Decomposition of a corpse is a continual process that can take from weeks to years, depending on the environment. To illustrate the process of decomposition, a piglet is used as the corpse.

Why piglets? A 40 kg pig resembles a human body in its fat distribution, cover of hair and ability to attract insects. These factors make pigs the next best things to humans when it comes to understanding the process of decay of the human body.

State of decay A live pig is not outwardly decomposing, but its intestine contains a diversity of bacteria.

Stage 2: Initial decay - 0 to 3 days after death                                                                                                      Although the body shortly after death appears fresh from the outside, the bacteria that before death were feeding on the contents of the intestine begin to digest the intestine itself. They eventually break out of the intestine and start digesting the surrounding internal organs. The body's own digestive enzymes (normally in the intestine) also spread through the body, contributing to its decomposition. From the moment of death flies are attracted to bodies. Without the normal defences of a living animal, blowflies and house flies are able to lay eggs around wounds and natural body openings

Stage 3: Putrefaction - 4 to 10 days after death Bacteria break down tissues and cells, releasing fluids into body cavities.The bacteria release an odor. People might find these gases foul smelling, but they are very attractive to a variety of insects. The build up of gas of the multiplying bacteria, creates pressure within the body. This pressure inflates the body and forces fluids out of cells and blood vessels and into the body cavity. Insect activity The young maggots move throughout the body, spreading bacteria and tearing tissues with their mouth hooks.

Maggots can consume 60 per cent of a corpse in less than a week.

Stage 4: Black putrefaction - 10 to 20 days after death The bloated body eventually collapses, leaving a flattened body whose flesh has a creamy consistency. The exposed parts of the body are black in colour and there is a very strong smell of decay. A large volume of body fluids drain from the body at this stage and seep into the surrounding soil. Other insects and mites feed on this material. The insects consume the bulk of the flesh and the body temperature increases with their activity.

By this stage, several generations of maggots are present on the body and some have become fully grown. They migrate from the body and bury themselves in the soil where they become pupae

Stage 5: Butyric fermentation - 20 to 50 days after death All the remaining flesh is removed over this period and the body dries out. It has a cheesy smell, caused by butyric acid, and this smell attracts a new suite of corpse organisms. The surface of the body that is in contact with the ground becomes covered with mould as the body ferments.

Grave wax, or adipocere, is a crumbly white, waxy substance that accumulates on those parts of the body that contain fat - the cheeks, breasts, abdomen and buttocks. Adipocere is resistant to bacteria and can protect a corpse, slowing further decomposition. Adipocere starts to form within a month after death and has been recorded on bodies that have been exhumed after 100 years.

Stage 6: Dry decay - 50-365 days after death The body is now dry and decays very slowly. Eventually all the hair disappears leaving the bones only.

decomp

Amount of food in the digestive tract Food in stomach yet – ate 0-4 hours ago Food in small intestine – ate 4-8 hours ago Food in large intestine – ate 8 – 12 hours ago Kind of food can show what last ate and maybe where Toxicology tests for poison

Vitreous humor – clear jelly-like liquid in the center of the eye Concentration of potassium (K) increases after death Good for up to 72 hours

ASSIGNMENT Find a partner to work with Time of death scenarios