The Body - A Guide for Occupants


How much do I want to read more? 8/10

Wow. I love reading all those facts about the human body. It really helps to grasp how amazing it is.
Just read this book and be in awe. You won't ever be the same. You won't ever look at your and your body as before.
It gives perspective. Your little problems are no more. It gives gratitude. The miracle of life suddenly is bigger than everything else.


1 HOW TO BUILD A HUMAN

according to RSC calculations, fifty-nine elements are needed to construct a human being. Six of these—carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus—account for 99.1 percent.
Plus some molybdenum, vanadium, manganese, tin, and copper.

The biggest component in any human, filling 61 percent, is oxygen.
It may seem a touch counterintuitive that we are almost two-thirds composed of an odorless gas. The reason we are not light and bouncy like a balloon is that the oxygen is mostly bound up with hydrogen (which accounts for another 10 percent of you) to make water.
It is a little ironic that two of the lightest things in nature, oxygen and hydrogen, when combined form one of the heaviest.
Oxygen and hydrogen are also two of the cheaper elements within you.

according to the RSC, the full cost of building a new human being: $151,578.46
Nova did an exactly equivalent analysis and came up with a figure of $168.

you blink fourteen thousand times a day—so much that your eyes are shut for twenty-three minutes of every waking day.
every second of every day your body undertakes a literally unquantifiable number of tasks—a quadrillion, a nonillion, a quindecillion, a vigintillion at all events some number vastly beyond imagining—without requiring an instant of your attention.
In the second or so since you started this sentence, your body has made a million red blood cells. They are already speeding around you, coursing through your veins, keeping you alive. Each of those red blood cells will rattle around you about 150,000 times, repeatedly delivering oxygen to your cells, and then, battered and useless, will present itself to other cells to be quietly killed off for the greater good of you.

Altogether it takes 7 billion billion billion (that’s 7,000,000,000,000,000,000,000,000,000, or 7 octillion) atoms to make you. They are mindless particles, after all, without a single thought or notion between them. Yet somehow for the length of your existence, they will build and maintain all the countless systems and structures necessary.

Your lungs, smoothed out, would cover a tennis court.
The length of all your blood vessels would take you two and a half times around Earth.
The most remarkable part of all is your DNA. You have a meter of it packed into every cell, and so many cells that if you formed all the DNA in your body into a single strand, it would stretch ten billion miles, to beyond Pluto. Think of it: there is enough of you to leave the solar system.

The cell is full of busy things—ribosomes and proteins, DNA, RNA, mitochondria, and much other cellular arcana. The cell itself is just a compartment—a kind of little room: a cell—to contain them, and of itself is as nonliving as any other room. Yet somehow when all of these things are brought together, you have life.

What is perhaps most remarkable is that nothing is in charge. Each component of the cell responds to signals from other components, all of them bumping and jostling like so many bumper cars, yet somehow all this random motion results in smooth, coordinated action, not just across the cell but across the whole body as cells communicate with other cells in different parts of your personal cosmos.