While most of us prefer not to think about what happens to our bodies once we shuffle off this mortal coil, forensic scientists and various other researchers find the topic fascinating. So much so, they have recorded the details of this natural process precisely and to a T (toe nail). Commonly, death is said to begin with the heart; when this vital organ stops beating, your breathing ends, and soon your brain stops functioning due to a lack of blood (and oxygen) flow.

However, the truth of the matter is your body does not die in quite so sudden or so orderly a fashion — different parts die at different rates, and the rates are somewhat variable depending on both your individual body and the circumstance of your death. What is certain is that after your heart stops beating, this creates a few key conditions. First, your blood stops flowing and begins to pool and settle wherever it is at in your body. Essentially, it congeals and turns your body purple and pink. Next, with no blood flowing, your body begins to turn cold, a phase known as algor mortis — or death chill to us laypeople. Hour by hour your body temperature will drop by 1.5 degrees (Fahrenheit), until it matches room temperature. Meanwhile, the more commonly known rigor mortis, when your dead body stiffens, occurs generally within two to six hours. At the same time, with no blood flow, your cells are becoming deprived of oxygen and so they have begun to individually die. Today scientists believe your brain cells don’t immediately disintegrate, so it may take hours for all the individual neurons to die and for your entire brain to be dead.

Your death, then, is actually many smaller deaths, occurring in domino-like fashion. As cells break down, they release enzymes which attract bacteria and fungi, contributing to the decomposition of your flesh and organs. After all your soft parts have been consumed, you’re a mere skeleton and over time, say 50 years, your bones will gradually disappear into other life forms as well.

For a quick review of the above, watch this YouTube video, courtesy of the American Chemical Society.

Now, while all this science is not too horrifying on paper, your body — or more accurately, your dead body — may provide a few hair-raising surprises for the unsuspecting observer. Prepare yourself for some grotesque-ry:

Hair and Nails

It’s a common myth that your hair and nails continue to grow after death. While this is not true, it certainly looks that way and that’s part of what frightens people. In fact, what happens is that, with no blood flow, your skin begins losing moisture after death. This lack of moisture causes your skin to shrink and pull back, which in turn reveals more of your hair (straight down to the follicle), while also exposing more of your nails. In other words, your hair and nails aren’t growing, they simply are unbared.

Reflexive Muscle Action

If by chance you come upon a dead body, stand back because it might kick you. Just a joke, but seriously, tissues continue to live for short while after your body’s death. As tissues, including muscle, die, they may contract, causing reflex like actions. Many doctors and nurses have reported seeing reflexive actions, including muscle twitches and muscles spasms, following the death of the heart. In fact, postmortem spasms have occurred (and been reported in the scientific literature) up to 12 hours after a body dies. Which leads us to our next point…

Erections

Depending on the position of your body at the time of your death, your blood will pool in a particular area and, because this blood still contains whatever oxygen and nutrients are left, it naturally feeds, one last time, the nearby cells, dying though they may be. After you die, the membranes of your cells become more permeable to calcium; certain types of muscle cells, meanwhile, are activated by calcium ions. End result? While ultimately this process leads to rigor mortis, in the shorter term, your muscles may contract. One (ahem) muscle in a man's body may contract and so cause an erection, which may even lead to ejaculation following death. Ladies, we warned you: stand back!

Pee and Poo

While some muscles spontaneously contract after death — and though all muscles eventually tighten into rigor mortis — others are loosening their grip entirely. Meanwhile, the part of your brain that regulates involuntary functions is shutting down. Specifically, the region of your brain that controls the muscles that hold your sphincter closed becomes incapacitated following death. Just like those rare occasions where you laughed so hard you peed in your pants, you will pee and poop in the spontaneous relaxation of your muscles following death. In fact, it’s not just the muscles but also the gas produced inside your body following death that will cause peeing and pooping. There’s really not much to say about this, right? Death is simply not pretty, nor was it meant to be.

Skin Cells

As noted above, different parts, tissues, and cells of your body will die at different rates; however, it is your skin cells that will live longest. Because they possess the strong advantage of being on the outside of you, your skin cells will absorb, through osmosis, whatever they can from the surrounding environment after you are technically dead. In fact, they will stay alive for days — days — on their own. Long live skin.

Heart-Stopping Sounds

Plug your ears! In the process of rigor mortis combined with a build-up of gas in your cavity, your stiffening muscles, including those that control your vocal cords, will prompt strange, sometimes hair-raising sounds to come from your dead body. Nurses and other hospital/hospice attendants have reported hearing moans, groans, and even squeaks coming from the dead. In a comment on allnurses.com, one nurse wrote, “Sometimes after death the body may make noises that sounds like it is breathing. I know of one instance where a resident died,was pronounced by the nurse,the doctor and family were notified. The staff went in to do the post mortem care-when they turned him he started 'breathing' again. ... They all freaked!”

Coffin Birth

Finally, what on earth could be more frightening than a dead body giving birth? German doctors first documented this phenomenon in the scientific literature and referred to it, then, as “coffin birth.” However, very rarely does a pregnant woman “give birth” after death. Officially referred to as “postmortem fetal extrusion,” what actually happens is a fetus is pushed through the vaginal opening of a decomposing pregnant body as a result of pressure from intra-abdominal gases. For this to occur, the fetus must be positioned just so and with the head set to emerge from the womb first. Two strange cases of postmortem birth have been recorded within the past decade.

In 2005, researchers at University of Hamburg recorded a case of a 34-year-old heroin addict in the eighth month of pregnancy who was found dead in her apartment with the head of a fetus partly protruding from underneath her slip. The autopsy determined there were no signs of external violence prior to death and also no indication of “preceding manipulations in the region of the obstetrical canal and the uterus.” Though not a live birth, the baby was pushed out after death due to the pressure of abdominal gases. In a separate 2007 case, a 23-year-old Indian woman who was over eight months pregnant hanged herself after her contractions had begun. Her body was found with a “viable infant” on the floor, still tethered to the body of the mother by the umbilical cord. Technically, the scientists say this is not a postmortem fetal extrusion, but simply a case of postmortem delivery.