"The Body: A Guide for Occupants"

[fiefoe]

Bill Bryson's brief guide to the human body could use an alternative title of '谁还没得过诺贝尔奖了' (to take a leaf from 非天的 《谁还不是个王子了 》).
Jokes aside, these are the names I noted down:
__ Henry Vandyke Carter, the co-creator and original illustrator of Gray's Anatomy,
__ Charles S. Sherrington, the pioneering neuroscientist who coined a famous metaphor for the human brain, "the enchanted loom".
__ Albert Schatz, co-discoverer of streptomycin could only publish in "Pakistan Dental Review", due to Selman Waksman's persecutions.

• A lung smoothed out would cover a tennis court, and airways within them would stretched from London to Moscow.
• The most remarkable part of all is your DNA. You have a metre of it packed into every cell, and so many cells that if you formed all the DNA in your body into a single fine strand it would stretch ten billion miles, to beyond Pluto. Think of it: there is enough of you to leave the solar system. You are in the most literal sense cosmic.
• DNA passes on information with extraordinary fidelity: it makes only about one error per every billion letters copied. Still, that works out at about three errors, or mutations, per cell division.
• The outermost surface of the epidermis, called the stratum corneum, is made up entirely of dead cells. It is an arresting thought that all that makes you lovely is deceased. Where body meets air, we are all cadavers. These outer skin cells are replaced every month. We shed skin copiously, almost carelessly: some twenty-five thousand flakes a minute, over a million pieces every hour. Run a finger along a dusty shelf, and you are in large part clearing a path through fragments of your former self. Silently and remorselessly we turn to dust.
• We have only thermal sensors to guide us, which is why when you sit down on a wet spot, you can’t generally tell whether it really is wet or just cold.
• Passionate kissing alone, according to one study, results in the transfer of up to one billion bacteria from one mouth to another, along with about 0.7 milligrams of protein, 0.45 milligrams of salt, 0.7 micrograms of fat, and 0.2 micrograms of “miscellaneous organic compounds” (that is, bits of food). But at soon as that part is over, the host microorganisms in both participants would begin a kind of giant sweeping-out process, and with a day or so the microbial profile for both parties would be more or less fully restored to what it was before they locked tongues.
• The herpes virus has endured for hundreds of millions of years and infects all kinds of animals, even oysters.
• A study in Switzerland in 2008 found that flu virus can survive on paper money for two and a half weeks if it is accompanied by a microdot of snot.
• Fanny had learned from her grandmother to use agar to make jellies because it didn't melt in the heat of American summer. Agar worked perfectly for lab purposes (i.e. growing medium for bacteria) too.
• The mold proved to be 200 times more potent than anything previously tested. The name and the location of the store Mary Hunt shopped are now forgotten... but the mold lived on. Every bit of penicillin made since that day is descended from that single random cantaloupe.
• Your brain is you. Everything else is just plumbing and scaffolding. Just sitting quietly, doing nothing at all, your brain churns through more information in thirty seconds than the Hubble Space Telescope has processed in thirty years. A morsel of cortex one cubic millimeter in size—about the size of a grain of sand—could hold two thousand terabytes of information, enough to store all the movies ever made, trailers included, or about 1.2 billion copies of this book.
• The lobotomy essentially destroyed Rosemary (Kennedy).
• What the eyebrows do really well is to convey feelings... One of the reasons Mona Lisa looks enigmatic is that she has no eyebrows.
• The chin is unique to humans and no one knows why we have one.
• You may have had the experience of looking at a clear blue sky in a sunny day and see little white sparks popping in and out of existence, like the briefest of shooting stars. What you are seeing, amazingly enough, is your own white blood cells, moving through a capillary in front of the retina. Because white blood cells are big, they sometimes get stuck briefly in the narrow capillaries.
• (Heart:) more litres (of blood) pushed through you in a day, than you are likely to put in your car in a year.
• Giraffes, oddly, sometimes have gallbladders and sometimes don't. 
• Just being kind, for instance. A study in New Zealand of diabetic patients in 2016 found that the proportion suffering severe complications was 40 per cent lower among patients treated by doctors rated high for compassion. As one observer put it, that is ‘comparable to the benefits seen with the most intensive medical therapy for diabetes’.
• There is a lot of other stuff in there, too - threaded blood vessels and nerves and tendons, and lots and lots of intestines, all of it just kind of tipped in, as if this poor, anonymous, former person had had to pack himself in a hurry. It was impossible to visualize how any of this disordered interior could ever have conducted the tasks that would allow the very inert body before us to sit and think and laugh and live.
• We have so much packed into the small space in the hand that a lot of work had to be done remotely, like strings on a marionette. If you make a tight fist, you feel the strain in your forearm.. that's because it's the arm muscles that are doing most of the work.
• Cartilage... has a friction coefficient five times less than ice. Imagine playing ice hockey on a surface so smooth that the skaters went sixteen times as fast. That's cartilage. But unlike ice, it isn't brittle.
• Bone is also the only tissue in the body that doesn't scar... Even more remarkably, bone will grow back to fill  a void.
• Tendons connect muscles to bone, ligaments connect bone to bone. Tendons are stretchy; ligaments, less so.
• Until recent times no other animals on earth was more likely to die in childbirth than humans. (Price of narrow pelvis for walking upright.)


• The average woman in the US today, weighs as much as the average man weighed in the 60s.
• Blagden managed ten minutes at a temperature of 198 degrees Fahrenheit. His friend the botanist Joseph Banks, managed 210 F.. for only 3 minutes.
• An increase of only a degree or so in body temperature has been shown to slow the replication rate of viruses by a factor of two hundred—an astonishing increase in self-defense from only a very modest rise in warmth.
• Although each electrical twitch at the cellular level produces just one hundred millivolts of energy, that translates as 30 million volts per meter - about the same as in a bolt of lightning.
• Most of the victims were captured Chinese soldiers, but Unit 731 also experimented on selected Allied prisoners of war to make sure that toxins and nerve agents had the same effects on Westerners as on Asians.
• In 1984 a student from Keio University in Tokyo came across a box of incriminating documents in a secondhand bookshop.. By this time, it was far too late to bring to justice Shiro Ishii.
• What Miller established was that the thymus is a nursery for T cells... It made Miller the last person to identify the function of a human organ.
• Inflammation is essentially the heat of battle as the body defends itself from damage. Blood vessels in the vicinity of an injury dilate, allowing more blood to flow to the site.. white blood cells can leave the circulatory system to pass through surrounding tissues, like an army patrol searching through jungle.
• "This sudden joining of transplantation and the immune system was a crucial point in medical science. It told us what immunity actually is."
• Allergies are a surprisingly recent concept, too. The word's first appearance in English... as only a little over a century ago.
• In breathing, as in everything in life, the numbers are staggering – indeed fantastical. Every time you breathe, you exhale some 25 sextillion (that’s 2.5 × 1022) molecules of oxygen – so many that with a day’s breathing you will in all likelihood inhale at least one molecule from the breaths of every person who has ever lived.1 And every person who lives from now until the sun burns out will from time to time breathe in a bit of you. At the atomic level, we are in a sense eternal.
• Air pressure in the chest is less than atmospheric pressure, which helps to keep the lungs inflated. If air gets into the chest... the differential vanishes and the lungs collapse to only about a third of their normal size.
• Sperm pass on none of their mitochondria during conception, so all mitochondrial information is transferred from generation to generation through mothers alone. Such a system means that there will be many extinctions along the way. A woman endows all her children with her mitochondria, but only her daughters have the mechanism to pass it onward to future generations. So if a woman has only sons or no children at all... her personal mitochondrial line will die with her. All her descendants will still have mitochondria, but it will come from other mothers on other genetic lines. In consequence, the human mitochondrial pool shrinks a little with every generation because of these localized extinctions. Over time, the mitochondrial pool for humans has shrunk so much that, almost unbelievably but rather wonderfully, we are all now descended from a single mitochondrial ancestor—a woman who lived in Africa about 200,000 years ago. You might have heard her referred to as Mitochondrial Eve. She is, in a sense, mother of us all.
• "When nerves are damaged, they do exactly the opposite - they switch on. Sometimes they just won't switch off, and that is when you get chronic pain."
• Thus was born chemotherapy... "We are basically still using mustard gases."
• In 1950, 216 children in every thousand.. died before the age of five. Today the figure is just 38.9 childhood death in a thousand.
• In London, life expectancy drops reliably by one year for every two stops travelled eastwards from Westminster on the District line of the underground.
• Eradicating (Alzheimer's).. would only add 19 days to life expectancy.
• Two other terms encountered commonly if no more productively (than telomeres) in discussions of aging, are free radicals and antioxidants.
• For each visual input, it takes a tiny but perceptible amount of time—about two hundred milliseconds, one-fifth of a second—for the information to travel along the optic nerves and into the brain to be processed and interpreted. One-fifth of a second is not a trivial span of time when a rapid response is required—to step back from an oncoming car, say, or to avoid a blow to the head. To help us deal better with this fractional lag, the brain does a truly extraordinary thing: it continuously forecasts what the world will be like a fifth of a second from now, and that is what it gives us as the present. That means that we never see the world as it is at this very instant, but rather as it will be a fraction of a moment in the future. We spend our whole lives, in other words, living in a world that doesn’t quite exist yet.
• All that is really going in your mouth is texture and chemicals. It is your brain that reads these scentless, flavorless molecules and vivifies them for your pleasure. Your brownie is sheet music. It is your brain that makes it a symphony.
• The nucleus accumbens, a region of the forebrain associated with pleasure, grows to its largest size in one’s teenage years. At the same time, the body produces more dopamine, the neurotransmitter that conveys pleasure, than it ever will again. That is why the sensations you feel as a teenager are more intense than at any other time of life. But it also means that seeking pleasure is an occupational hazard for teenagers.
• The most universal expression of all is a smile, which is rather a nice thought. No society has ever been found that doesn’t respond to smiles in the same way. True smiles are brief—between two-thirds of a second and four seconds. That’s why a held smile begins to look menacing... a genuine, spontaneous smile involves the contraction of the orbicularis oculi muscle in each eye, and we have no independent control over those muscles.
• (Thin people have more gut microbes than fat people; having hungry microbes may at least partly account for their thinness.)
• a mouse’s beats six hundred times a minute—ten times a second. Every day, just to survive, the mouse must eat about 50 percent of its own body weight. We humans, by contrast, need to consume only about 2 percent of our body weight to supply our energy requirements. One area where animals are curiously—almost eerily—uniform is with the number of heartbeats they have in a lifetime. Despite the vast differences in heart rates, nearly all animals have about 800 million heartbeats in them if they live an average life. The exception is humans. We pass 800 million heartbeats after twenty-five years, and just keep on going for another fifty years and 1.6 billion heartbeats or so. It is tempting to attribute this exceptional vigor to some innate superiority on our part, but in fact it is only over the last ten or twelve generations that we have deviated from the standard mammalian pattern thanks to improvements in our life expectancy. For most of our history, 800 million beats per lifetime was about the human average, too.
• What leptin is there for essentially is to tell the brain whether you have enough energy reserves to undertake comparatively demanding challenges like getting pregnant or starting puberty. If your hormones think you are starving, those processes will not be allowed to begin... “It’s also almost certainly why puberty starts years earlier now than it did in historic times,” says Wass. “In Henry VIII’s reign, puberty started at sixteen or seventeen. Now it is more commonly eleven. That’s almost certainly because of improved nutrition.”
• as horripilation but more commonly as getting goose bumps. In furry mammals, it adds a useful layer of insulating air between the hair and the skin, but in humans it has absolutely no physiological benefit and merely reminds us how comparatively bald we are. Horripilation also makes mammalian hair stand up (to make animals look bigger and more ferocious), which is why we get goose bumps when we are frightened or on edge, but of course that doesn’t work very well for humans either.
• Broken hips are especially challenging for the elderly. About 40 percent of people over seventy-five who break their hips are no longer able to care for themselves. For many, it is a kind of last straw. Ten percent die within thirty days, and nearly 30 percent die within twelve months. As the British surgeon and anatomist Sir Astley Cooper liked to quip, “We enter the world through the pelvis and leave it through the hip.