[Lewis Thomson (OP)]

Donald is looking for answers to this question.

"The digestive system has many clever means to prevent autodigestion. Obviously if it goes wrong just once, severe to lethal consequences occur. Obviously, also, there are many such insults or occurrences that have similar catastrophic outcomes, like cardiac dysrhythmia, choking on food, aspiration of vomit, inappropriate clotting, etc. To keep homeostasis seems impossibly complex and one error fatal, suggests a lot of luck as complex system have higher entropy, more breakdowns, more points of critical errors, and more ways to die. How lucky is a man to live to 80? That is, can science quantify this ability to avoid entropy?"

Leave your answers in the comments below...

[alancalverd]

Two characteristics of living things are self-repair and defect tolerance - the first being a unique feature not shared by other machines. So "one error fatal" is not generally true. Some single errors (cancer) do propagate and eventually interfere with a critical function, but death for most of us is the result of many interconnected subsystems being unable to selfrepair as quickly as they wear out or are subject to external insult.

Over the last 200 years or so we have tamed or eliminated many of the external insults, and life expectancy has tripled.

[Bored chemist]

The digestive system has many clever means to prevent autodigestion. Obviously if it goes wrong just once, severe to lethal consequences occur.

Plenty of people survive ulcers.

[evan_au]

As we get older, cells in many organs become "senescent", consuming space and resources, but not actually doing much.
- It is the steady accumulation of senescent cells that makes all organs become less efficient.
- Some have suggested that waking up or getting rid of senescent cells might improve organ effectiveness
- But it might equally activate cells that then become cancerous and kill you
See: https://en.wikipedia.org/wiki/Cellular_senescence

[alancalverd]

As we get older, cells in many organs become "senescent", consuming space and resources, but not actually doing much.

But I still love my brain. It's a bit like an old dog, or a barren hen - useless, but full of happy memories.