Here we'll explore the biological process of death and also clear up some basic questions about the science of it all. Find out how the mind reacts to death and how people try to cope with it. Death is treated very differently all around the world. Here we'll discuss the various religious and cultural differences. Discover the social implications of death and how death affects society. Discuss death related topics with other surfers.

Science 99 ways to die (Well, not really. We don't have time to be that mordbid) The Post-Mortem Process Regardless of the manner in which one meets their end, unless the body is severely mutilated, there is a very distinct series of occurrences that take place in a dead human body. Once the energy-producing system ceases to function-- by lack of oxygen or nutrients-- death occurs, and -the eyes turn cloudy and sink in to be level instead of rounded, which happens very soon after brain death. It is an easy way to tell if someone is past the point where CPR can return life. -the body begins to cool to the temperature of the surroundings. This is known as algor mortis, and the length of time it takes to happen varies from minutes to a few hours. As with any cooling object, the body cools from the outside in. -all of the blood clots and then settles to the lowest parts of the body, as any liquid does in a container. Livor mortis is the settling of the blood, causing the places in which it rests to discolor to a bluish-red. -the face loses the natural radiance of life. More than just the loss of color, experts say there is a certain look to a dead face that is unmistakable even to one who has never before seen a corpse. -muscle tissue stiffens everywhere in the body, occurring within a few hours and lasting up to five days. Actin and myosin produced by the muscles, substances that can't be processed by a dead body, form together into a gel which hardens. -tissues are broken down by enzymes released after the death of a tissue's cells, a process called autolysins. Initially, this process is only internal. Skin is the last to decay, and that takes days. -microbes in the intestine break down the blood, rupture the intestine, then break down other internal organs. Putrefaction, internal bacteria and other microbes causing decay, is the main cause of decay, not external microbes. The process of putrefaction does start until about two days following death. -the body warms due to the chemical reactions of decay. -swelling occurs from gases produced by putrefaction. -a strong odor develops from decay. -the skin begins to get creamy, and black streaks and patches are exposed. -collapsing in on itself, the body seems to deflate, as gases escape -the body dries out Heart Disease Poor diet, smoking, sedentary lifestyle, and other factors can lead to a buildup of fat and cholesterol in the arteries which, besides being a rather unsightly mess for the blood cells to look upon, both narrows and hardens them, a condition called arteriosclerosis. It can have an especially severe effect of the coronary arteries (ironically enough), which supply the heart muscles with blood so it can continue to have energy to pump. It is also a fact that arteries get bigger and smaller depending on the body's activity. Arteries constrict usually when there is physical exertion, for example, and dilate (enlarge) when at rest. If there is enough plaque buildup, upon such constriction the coronary arteries have just enough plaque to start affecting oxygen flow to the heart muscles. At first this just causes chest pains, and sometimes pain in an arm as well, and when physical exertion stops the arteries get bigger and the problem subsides. There comes a point, though, when the coronary arteries are narrowed to the point where the heart muscles get less oxygen than they need to function. Between normal constriction and too much plaque buildup, there's just not enough oxygen, and the heart stops and heart tissue begins to die. Or constriction can break off a chunk of plaque and completely block the coronary arteries, and to add insult to injury, blood clots around it making it more massive. Either way, heart muscle tissue starts to die from lack of oxygen, and the heart can no longer pump blood to the rest of the body. This is heart attack, or myocardial infarction. The brain is the first to be affected when circulation stops. Nervous tissue is very complex, and while that makes it do miraculous things, it also makes it sensitive to oxygen deprivation. First the brain shuts down, focusing on cell survival instead of activity and function. Soon brain cells begin to die, within 4 to 7 minutes. This is the period in which CPR might be able to return life again, but after this short interval, the tissue is destroyed beyond possible future function. Other tissues follow suit shortly after. Asphyxiation Asphyxiation is the dangerous state that occurs when oxygen does not get from the lungs to the blood as normal. Many things can lead to asphyxiation including suffocation, serious chest injury, and respiratory infection. The absence of oxygen to breathe, suffocation, means no oxygen is getting into the lungs in the first place. Another way is a chest injury, which can lead to blood filling the lungs and thus leaving no room for air. With a respiratory infection like pneumonia or bronchitis, infection kills oxygen-absorbing lung tissues and/or produces sputum that blocks oxygen from reaching such important tissues. Finding month-old cheese in the back of the fridge has also been known to cause asphyxiation, but the medical field refuses to support such claims. Moving on. With any of these causes, oxygen can't get absorbed into the blood and delivered throughout the body. The brain being the sensitive organ it is stops functioning first, starting with the upper levels like the cerebrum and causing unconsciousness. It isn't dead yet, just not functioning. The heart still beats because the brain stem continues to function, sending it's regular impulses to the heart muscles-- although, with no oxygen getting into the bloodstream, circulation has no point anyway. Within a couple minutes the brain stem stops activity and all that it controls stops as well, including the heart. After about four minutes brain cells can't survive any longer without oxygen and the brain dies. After this point CPR isn't effective because the brain has been destroyed. Other tissues die in from a half-hour to an hour thereafter. Lacerations and Nasty Bruises From a laceration such as from a knife or pointy stick, the skin is broken and bleeding occurs (It happens. Fear the pointy stick.) Bleeding from such an open wound can be inside the body as well as outside. But bleeding can also be completely inside the body. In such cases, no skin is broken, but blood vessels and/or organs are damages and bleeding occurs. This comes usually from some sort of focused impact, like a punch or some other blow. Car accident deaths usually occur from some combination of these two, lacerations (gashes) and internal injury from impact. When the bleeding is internal, the blood just flows into various nooks and crannies-- in between organs for example. But that's the only difference between external and internal. Be careful, though, because in medicine the phrase "internal bleeding" refers specifically bleeding into the gastrointestinal tract (stomach and intestines). Besides being very painful, one can lose a large amount of blood if the wound is large or breaks open a major artery such as the ones in the neck, groin, and leg. If an organ is lacerated it will definitely increase bleeding. All organs need a lot of blood to function, so organ tissue is filled to the brim with all kids of capillaries bring blood to all parts of the tissue. Excessive bleeding means there isn't enough blood supplying oxygen to the tissues that need it. The brain can't function and shuts down, and in addition its cells being to die quickly, much more so than any other cells in the body. Brain cells can't survive without oxygen for more than about 4 minutes. It's a period of 4 to 7 minutes in which CPR can be effective in restoring life, but usually irreversible damage has been done that will continue to affect the person. Since the brain controls the heart, the heart stops functioning as soon as the brain does-- not that it matters too much because there isn't much blood to pump. After about 7 minutes, the brain is completely dead. Other tissues die soon thereafter. If the lungs are ruptured, blood seeps into and fills the lungs which impedes oxygen intake, and can cause [asphyxiation] as well. Since the stomach and esophagus are connected to the lungs through the trachea, if they are ruptured blood can also flow into the lungs, and in that manner cause asphyxiation. Cancer There are varying types of cancer, classified by the kind of tissue it originates in. The most common, however, is the carcinoma, which take form in cancers of the skin, the lining of organs, and the tissue of the breast and prostate glands. How cells grow and reproduce are regulated by certain biological processes. But sometimes, because obviously it's mother didn't teach it any manners, a cell doesn't do what it's told. It uses an enzyme called telomerase to reproduce like there's no tomorrow-- much like rabbits. Except rabbits don't form tumors. These renegade cells do. Known as "free radicals," they amass into a growth on whatever tissue they originate from. It's important to note that, while most cancers for tumors, not all tumors are cancerous. In fact, the majority of tumors are "benign," literally meaning they have no negative effects. Such tumor cells function as a regular part of the organ or tissue. They're just an unsightly deformity to passing blood cells. "Malignant" tumors are different. It wouldn't be so bad if free radicals continues to function normally. But instead they don't fully mature and thus become of no use whatsoever. What's worse, they spread, taking up nutrients and thereby depriving healthy functioning cells from reproducing themselves. In addition to affecting the tissue of origin, cancerous cells can spread to nearby organs and tissues, causing the same disruptive effects: using nutrients so healthy cells can't be made. Free radicals can also break off from the tumor and get into the bloodstream, migrating to far-off locations in the body and causing cancer there as well, a sort of secondary tumor known as a metastasis. Or the cells may form a tiny clump and just stop growing, continuing to circulate in the bloodstream or lodging in some crevice. But later, for reasons still unknown, such clumps of broken-off cancer cells can become active again, and cause a recurrent cancer, sometimes years later. Cancer destroys organs and tissues. If that organ can't function, then it disrupts the energy-making process in which its existence is necessary. The body can no longer survive. The brain shuts down, and its tissue begins to die within a few short minutes, usually 4-7. CPR is normally ineffective, since the entire body system is damaged. Heart tissue dies in about 15 minutes, and other tissues follow shortly after that. Stroke Two things can cause stroke. The first is blockage in an artery in the brain, caused usually by a buildup of plaque in the main arteries leading to the brain, in much the same manner as arteriosclerosis in [heart disease]. Or a piece of plaque from a diseased heart can break off, travel in the bloodstream and lodge in a cerebral artery. In either case the result is the same. Further on past the point of blockage, tissues don't get oxygen and die. The second is when a cerebral artery ruptures, almost always originating from a blister-like bulge called an aneurysm, which expands and weakens a small part of a cerebral artery. Much like the blockage described above, blood supply is then cut off to tissues. In addition, the seeping of blood into the brain can cause high amounts of pressure, causing the brain to cease function and eventually die. Brain cells are more sensitive to oxygen deprivation that any other cells in the body. First the brain gets weak in function. Then it ceases to function, and after about 4 minutes tissue starts to die. After 7 minutes the entire brain is usually dead-- which is why time is a critical factor in CPR. After about seven minutes of oxygen deprivation in the brain, too many cells have died and the possibility of returning life to the victim no longer exists. Heart tissue dies after about 15 minutes of oxygen deprivation, and within an hour most other tissues die as well. Copyright 2001. Created by a Thinkquest team. Feel free to email us at C0122781@thinkquest.org.