Journey with us as we explore the fascinating and sometimes unsettling processes that occur after death. From the immediate cellular breakdown to the final stages of decomposition, we'll examine the biological changes that transform our bodies. Warning: This content contains detailed scientific explanations of post-mortem processes.
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00:00The fresh stage begins immediately after the heart stops beating.
00:03Welcome to WatchMojo, and today we'll be looking at the most fascinating stages of the decomposition process that unfold after a person dies.
00:11Now in order to understand why somebody gets very stiff with their muscles post-death, we need to have a look at how muscles contract.
00:19Cells start to break down. As living beings, our hearts continuously pump blood throughout our bodies, transporting oxygen to cells and taking away their waste products.
00:29Blood goes from one heart pump to the lungs, back to the second heart pump, which sends it to the body, and then back to the first pump.
00:36However, when a person dies, their heart ceases to function, leaving cells with no means to eliminate their waste.
00:43This causes a toxic buildup that greatly increases the acidity within the cells.
00:47Once this occurs, certain internal membranes start to rupture, allowing enzymes to be released and roam freely.
00:53In necrosis, there is a loss of integrity of the wall of the cell, which leads to swelling of the cell's contents, as well as disintegration of small bodies of the cell.
01:02These enzymes initiate a process called autolysis, in which they digest the internal structures of the cells, essentially consuming them from the inside out.
01:11It also breaks open capillaries, releasing blood cells that turn the skin a pale purple.
01:17This typically starts off in the liver and brain a few minutes after death, before spreading throughout the rest of the body.
01:23Burst of brain activity
01:24Many people who have had near-death experiences often describe seeing their entire lives flash before their eyes, or having an out-of-body episode just before they're resuscitated.
01:34Images of childhood come back to you. You're selling lemonade on the street outside your house.
01:38Then you're a teenager holding hands with the person who was your first love.
01:41For decades, this phenomenon baffled scientists, as they believe that brain activity essentially stopped along with the heart.
01:48However, studies have shown that for a brief period after death, the brain experiences a sudden surge of electrical activity, sometimes exceeding the level seen during the normal waking state.
01:58This may result in a state of intense hallucinations, which can last up to five minutes in some cases.
02:04The dying patient's brainwave patterns appear to correlate with those who have had a near-death experience.
02:09This suggests that the body enters a heightened form of consciousness immediately after death, before eventually giving out completely.
02:16Am I merely seeing nerve cells firing and brainwaves being active, or do they have a functional meaning and they let us perceive these memories and recalls?
02:26That, to me, is the biggest question.
02:28Body temperature drops. It is well known that when a person dies, their bodies typically grow colder than usual.
02:34Without the heart beating, blood cannot distribute heat and regulate body temperature.
02:39This leads to the body temperature reaching equilibrium with the external temperature.
02:43This process, which is recognized as the third stage of death, is referred to as algor mortis.
02:48In a living human, body temperature is controlled by the hypothalamus, located within the brain.
02:53The hypothalamus is a small region situated directly above the brainstem.
02:56But after life ceases, the body temperature gradually decreases until it aligns with that of the surrounding environment.
03:03Usually, this cooling process occurs at a rate of 1.5 degrees Fahrenheit per hour.
03:08However, the speed of this decline also depends on a variety of factors, including the environmental conditions,
03:14the type of clothing worn by the deceased, as well as any underlying diseases.
03:18Bloating.
03:19The human body is populated by millions of microorganisms, largely composed of bacteria.
03:23And it's not just bacteria.
03:26We're home to populations of viruses, fungi, and archaea too.
03:31These microbes are sometimes beneficial to us and are prevented from causing infections by the immune system.
03:36So what happens when this system no longer functions?
03:39In a process known as putrefaction, the bacteria begin to consume the body tissues
03:44and produce gaseous compounds such as methane and ammonia as byproducts.
03:48There can be cases of infections and inflammations already found in the body that will speed up the process of putrefaction.
03:55These gases build up within the body, causing it to bloat, primarily in the abdomen and chest areas.
04:01Additionally, as some of the bacteria attack the blood cells, it results in the production of a greenish molecule,
04:08which accumulates and causes a discoloration of the skin.
04:11He's quite the guy, despite the fact that he's blue.
04:16Moaning and groaning.
04:17Hearing the dead make audible noises is something that would definitely freak most people out.
04:21But surprisingly, it is a relatively common occurrence.
04:24And especially when we're, you know, really washing it or embalming and you're putting some pressure on,
04:29you can push in and you hear this.
04:31Much like zombies in a work of fiction, corpses can actually let out moans and groans long after they're dead.
04:38This phenomenon occurs due to the presence of air in a person's lungs at the time of death.
04:43When the body is moved around in a certain manner, this trapped air could be released through the vocal cords,
04:49creating sounds that resemble moans or groans.
04:51So because it's sucking air through it, it's bringing air in through the voice box and it's making all that noise.
04:57This commonly happens with individuals on whom medical personnel tried resuscitation.
05:02But it could still occur, even if no such efforts were made.
05:05I just stopped what I was doing because, oh my god, I thought I was hurting the person.
05:10Nails and hair appear to grow.
05:12You might be familiar with the notion that after a person dies, their nails and hair continue to grow.
05:18While it may seem true at first glance, it's not at all accurate.
05:21Factoids with creep factor are always fun to repeat, especially around the campfire.
05:27But this often repeated statement is not what it seems.
05:31The process by which these body parts grow require a significant supply of energy from glucose.
05:37Cells at the base of the hair follicle rapidly divide to make new cells to grow hair.
05:42But they need energy. Energy comes from burning glucose.
05:45When a person dies, however, this energy source is no longer available.
05:49And as a result, nail and hair growth effectively cease.
05:52However, the reason why this misconception has become so popular is that after death,
05:57the skin becomes dehydrated and shrinks.
06:00This causes the nails and hair underneath to become more prominent.
06:03And morticians actually have all sorts of creams and plumpers to combat dehydrated skin.
06:10You may still relieve yourself.
06:12Located in the bladder and bowels are certain sphincters that allow you to control the release of pee and poop.
06:19These two vital organs work together to get rid of waste products,
06:22and we need them to function optimally so that we can function optimally.
06:27However, shortly after death, all the muscles in the body, including these sphincters,
06:31undergo a process called primary flaccidity, in which they become relaxed.
06:35As the pressure increases, bodily fluids and gases push out of any orifice.
06:40As a result, any urine in the bladder or feces in the rectum will pass out freely.
06:46This may not happen as forcefully as during a visit to the restroom,
06:49as the muscles that help push out waste will also be relaxed.
06:52It is worth noting, though, that this involuntary release doesn't happen in every deceased person.
06:57According to most morticians, it occurs in only around 20 to 50 percent of corpses.
07:02So the actual answer to the question, do corpses soil themselves, is, yeah, they sometimes do.
07:10Liver mortis.
07:11When a person dies, their heart stops functioning, and circulation of blood throughout the body effectively ceases.
07:17Without the pumping action of the heart, blood remains stagnant within the vessels.
07:21It pools wherever the forces of gravity is strongest.
07:23About 20 to 30 minutes after death, gravity slowly causes the blood to pool at the lowest points of the body.
07:30This results in the characteristic pale appearance of corpses when they lie face up.
07:35Roughly two hours post-mortem, the pooled blood causes large purple splotches to appear at the bottom of the body.
07:41The normal color of liver mortis changes from red to purple, as oxygen gradually disassociated from the hemoglobin.
07:50This phenomenon is known as liver mortis, and it serves as one of the observable signs of death.
07:55In some cases, coroners also use liver mortis to estimate the approximate time of death.
08:00So that will give us the full amount of time that this person has been dead.
08:05So that is 29.02 hours since they died.
08:12Rigor mortis.
08:13Following the initial relaxation of the body during primary flaccidity,
08:17the muscles in the body undergo a series of chemical changes that lead them in the complete opposite direction.
08:23This phenomenon is referred to as rigor mortis, another observable sign of death.
08:27Now this is a Latin term. Rigor means stiff, mortis means death.
08:31Rigor mortis usually sets in between two to six hours after death,
08:35causing all the muscles in the body to contract and become stiff.
08:39While I'm washing the deceased, I'll massage all the muscles and the joints and move them.
08:46It's a common misconception that this process begins immediately after death and stays permanently.
08:52In reality, however, it typically lasts for several hours before the muscles eventually return to their relaxed state,
08:58a process known as secondary flaccidity.
09:01By the time I've done all that, and I come to dress them, they're quite loose again.
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09:18The decomposition of a corpse typically starts with the aforementioned autolysis,
09:27where the cells are broken down by enzymes, and ends with skeletonization.
09:31Finally, in the advanced stage, the body will continue to break down.
09:35As the name suggests, this state occurs when all the soft tissues in the corpse have decayed
09:41or have been consumed completely, leaving behind just the skeleton.
09:44After 80 years in that coffin, your bones will crack as the soft collagen inside them deteriorates,
09:52leaving nothing but the brittle mineral frame behind.
09:54The time it takes for this process to happen depends on a range of factors,
09:58such as the temperature of the environment and the presence of insects.
10:02Overall, it varies from around three weeks to several years.
10:06Once skeletonized, the corpse can remain largely intact for decades or even centuries,
10:11making it valuable as forensic evidence or for archaeological purposes.
10:16A human skeleton expected to be at least 100 years old
10:19found by a family on their newly purchased property in LeFleur County.
10:23Which of these facts about death terrifies you the most?
10:27Let us know in the comments below!
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