I was at the beach today thinking I’m basically just a slab of meat in the sun. How come I don’t rot? What prevents living things from decomposing and how does that change when we die?
In: Biology
We do actually. Thing is, we can regenerate faster than we rot. And immune system slows this down a lot
While we’re alive, we’re constantly making new cells to replace the ones that degrade/rot. When we die, we stop making new cells (because blood flow and respiration drive that engine), so everything degrades without being replaced.
Our body can reverse entropy and keep decay at bay faster than the decay can happen. We constantly break down and regenerate bones and muscle, regenerate our cells in our digestive system and skin among other organs. It’s everywhere.
The immune system. The job of the immune system is to stop microorganisms from causing you to rot while you’re alive. It hunts down invaders and kills them. When it fails you get things like flesh eating bacteria, gangrene………….
When you die, you stop breathing and your heart stops pumping blood round the body. This prevents oxygen (needed to convert energy-containing nutrients into actual energy) and required nutrients from reaching cells. It also prevents waste products from those cells from being flushed to the places where they can be processed (the liver and kidneys). They build up near the cells. So the chemical balance in your body starts to change. In addition, without blood-flow and the means to regulate cell activity, the body temperature starts to change, usually cooling, but sometimes heating up.
These changing conditions then allow some of the bacteria already in the body to grow in ways that they could not previously. In addition, without blood flow, there is no immune response to suppress those bacteria. In particular, bacteria that live without oxygen (anaerobic bacteria) flourish – these bacteria often produce gases like methane and Hydrogen Sulphide.
In the gut there are many different types of bacteria. Since food transport (peristalsis) has stopped, they just go to work on the remaining food in the gut, and each other. Again, the changing conditions favour anaerobic bacteria, and this creates large amounts of gas in the alimentary tract, causing bloating. Eventually the bacteria start on the gut lining, and into the rest of the body.
If you can keep supplying oxygen and maintain heartbeat, you can keep a “dead” body viable for a few days, as in the case of brain-dead patients on life support.
If circulation is impaired on a part of someone who is alive, necrosis (dead and rotting tissue) can set in.
The cells in your body that do die are handled in a controlled manner. Phagocytes consume damaged and dying cells. The kidneys filter out harmful materials out of the blood, including the contents of cell interiors. The liver neutralizes toxins, again, some of which may have been released. Many other bodily systems help maintain balance—salinity, acidity/alkalinity, temperature, etc.
A lot of other cells in your body die regularly, but are eventually exposed to the outside world. The outer layer of your skin is dead, but also pretty durable and resistant. Same for your hair. Certain cells inside of your mouth, stomach, and intestines are abraded as food passes along; these cells eventually join your food and the community of microbes that exist in your gut, or wind up in the toilet.
Everything else is kept alive by the steady flow of oxygen and nutrients, and favorable conditions (tolerable temperature, moderate air pressure, etc.). When conditions are no longer favorable, and there is no further intake of oxygen and nutrients, the rate of cell death overwhelms what the body can clear, and other organisms can take advantage of the new environment and failing immune response. Membranes degrade, allowing more freedom of movement. Toxic substances accumulate. Complex structures break down, becoming food and debris for other forms of life. Anaerobic microbes that were earlier halted by oxygen, are now free to roam.
Rotting is basically bacteria eating something and pooping. That’s why it’s so smelly. It’s easy for bacteria to eat dead things and poop, but things that are alive are hard for them to eat because they can fight back.
Sometimes they do. Google gangrene or weeping wounds that do not heal. Then look up necrosis in living humans. Then lung disease where the lungs rot in the body.
Oh then there are the mites in your eyebrows that eat your skin.
Fungus in your ears, toes and crotch if you are unlucky.
There are parasites that eat you alive.
Body odor is the excretions from bacteria eating your body oils.
Teeth rot in your mouth. Right now your mouth is an orgy of decay.
Also remember your very survival depends on bacteria in your gut rotting away in a balanced way the food you eat.
The world is eating you alive every day, it is just when the major organs fail and you die the balance is shifted to complete decay.
Actually, you ARE rotting. Your immune system is fighting the microbes currently trying to rot you, and the rest of your body is busy regenerating what little success these microbes have.
No heartbeat = no immune system = no nutrients coming to cells to allow reproduction and repair
Can someone explain old people smell to this poor fellow?
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