Decomposition

I found this article...sorry, I dont have the link...but its pretty cool...the stages of decomposition

STAGE 1 FRESH

After the Five Minutes of somatic death (a human body takes approximately 5 minutes for all organs and bodily functions to cease) a corpse begins decomposing (also the moment a typical zombie reanimates). Human decomposition is comprised of two processes: autolysis and putrefaction.
Autolysis also known as self-digestion is the body’s cellular revolt. Oxygen starved cells melt and dissolve, releasing nutrients into the body, and providing fertile breeding ground for putrefaction. At the same time, digestive enzymes continue to work without the controls present in life. The gastrointestinal tract ceases to make protective mucus, which normally lines the organ tissue and guards against the destructive enzymes. Unchecked, these fluids perforate the walls of the intestine, stomach, lower esophagus, and eventually, the lung cavity. Essentially, the body begins to digest itself and during this first phase of decomposition, most of the organs will be busy transforming into a liquid mess. Autolysis is unnoticeable during the few days of death, but eventually fluid filled blisters appear on the skin, and skin slippage occurs, where the outer layer of dermis loses adhesiveness and large sheets of slimy king slough away easily.

The Brain high in water content also begins to turn to mush. However, encased within the skull retains its location and general shape. The first part of the brain that softens with autolysis is the frontal lobe, an area largely unused by the undead, so performance not noticeable impaired, relatively speaking.
The second and more major component of decomposition, putrefaction is the post mortem destruction of the soft tissues of the body by the action of bacteria. Without the natural defenses of a living body, the bacteria multiply and eat away at the tissue eventually reducing everything to liquid. Typically the first visible sign of putrefaction is a greenish discoloration of the abdomen, where the bowels fill with bacteria-laden fluid. This discoloration slowly spreads to the flanks, chests, limbs and face. The superficial veins of the skin become purple-brown and invisible, giving the appearance of “marbled” skin. Deceased who lost a lot of blood putrefy at a slower rate, because the bacteria are denied the use of blood as a vehicle to multiply in. Air temperatures below 70 degrees Fahrenheit tend to retard putrefaction, and if the weather is cold enough, putrefaction may be halted altogether, many other variables can affect the process: OBESE bodies and wet weather accelerates Putrefaction, while dry weather can desiccate a corpse, slowing decay.

Other changes occur, including algor, livor and rigor mortis. Algor mortis is the post mortem cooling of the body; the zombie cools at the average rate of 1.5 degrees per hour, until reaching ambient environmental temperature.
Two hours after death, the zombie’s red blood cells separate from plasma and settle towards the lowest part of the body (i.e., if the body has been dead a few days, positioned face up, the blood settles into its back; if the undead is animated minutes after death, then gets up and resumes walking, the blood sinks down into its legs and feet). This is called LIVOR MORTIS— or fixed lividity— and is the main reason why blood seepage is so often absent from post mortem wounds. The pooled blood gives the flesh a permanent, reddish-purple-maroon color, which can be mistaken for large bruises.
Rigor mortis, the muscular rigidity due to lactic acid buildup, can usually be found within a few hours. All the muscles start to harden at the same time, but the smaller ones fully stiffen first. Rigid limbs can be forced to move by bending them until the muscle “Breaks” (accompanied by a grotesque crepitating snap) which releases the lactic acid. A zombie cannot do this by itself. Rigor mortis usually lasts about 12 hours, until it reaches its peak and starts to gradually subside until the body is slack. A zombie caught in rigor is paralyzed and completely vulnerable to attack.
The undead quickly make new friend. Mere moments after death, the body attracts a legion of necrophagous devotees. Blowflies are the first to lay their eggs. After the first day of death, the corpse teems with maggots, which congregate in wound sites and other soft tissues of the outer body (eyes, mouth, genitalia etc.), this attracts beetles and other insects who often prey upon the maggots, but in the case of a shambling zombie, most insects and larva are jostled free from their undead host, so insect feeding is negligible.
Several days after death, the body begins to warm again, the violent putrefaction of the tissues and inner organs so intense that the corpse’s temperature sometimes increases to 100 degrees farenheit. Any person touching a zombie a few weeks into the fresh stage notes a sick, hot radiance.

STAGE 2 BLOAT
The second stage is characterized by massive swelling- known as tumefaction- where putrefaction from bacteria activity creates a buildup of gases, which bloat the body (sometimes to twice the normal size in stationary dead). Throughout this second stage, the body slowly dissipates the gas through orifices and wound sites. Undead don’t swell to these impressive extremes, as they’re constantly moving and pushing gases from their bodies, negating any chance to build up. This gas seepage makes the living dead twice as pungent smelling. During the Bloat stage, skin increases in elasticity and continues to slough from the body. The raw tissue beneath is glistening pink and eventually dries out, taking the appearance of yellowish leather. Of course, all this deterioration also makes the zombie truly horrifying to look at, so there is an upside.
Internal organs are all but mush by the end of this stage, and slosh around in the torso until vomited by bending forwards to feast or falling over. The esophagus, diaphragm and lungs have melted by this point, making speech-or any vocal noise—impossible. Hair and finger nails are loosened and can be easily yanked from the body. The muscular structure is still in decent condition, but the tendon and ligament attachments have been damaged by the decay.
After the height of bloat, when most of the putrefactive fluid is purged from the undead, the body temperature cools again to environmental conditions.

STAGE 3 DECAY

At this stage, the skin turns from green to black. Bloating has completely subsided and the body has sunken in on itself, the inner cavities largely empty and lacking solidity. The muscles deteriorate, and tendons and ligaments detach piece by piece. Simply put, the body begins falling apart. During this stage, the undead start to lose the use of their limbs. The R complex succumbs to decay, and the zombie spends most of the time writhing on the ground in confusion, until the brain stem finally loses its power of reanimation and the living dead experiences final death. This point is reached halfway between Stage 3 and Stage 4.
Th
e corpse continues to decompose, finally assisted by animals and insects previously denied predation right. Larger animals such as birds, dogs, or cats often come to worry at the body. The zombie may have its own way of discouraging this activity, since dog flesh might prove to be an acceptable ( if temporary) substitute for the human sort. Still, the sight of a wild dog pack taking down a lone zombie may be encouraging to you… Until the dogs spot YOU ^_^
The cadaver will reach skeletonization at the beginning of stage IV, the final day of its unlife expectancy.

STAGE 4 SKELETONIZATION
The body achieves complete skeletonization. Only tissue- littered bones remain. The zombie is truly and finally dead.