June 18, 2013 7:30:10 AM
You've got a body that works fairly well, all things considered, even if it doesn't work as efficiently and painlessly as it did ten years ago. No one knows that body as well as you do, but almost everything it does inside goes on in secret, even from you, the person ostensibly in charge. The anatomists might have a deeper idea of what innards do, but even they haven't solved all the issues; they have been dissecting eyes for centuries, for example, and just last week it was announced that a new, hitherto unknown layer has been found. We can do little but relish the mysteries, and admire the astonishing refinement of our bodies to do what they need to do and what we want them to do, and these are among the fine lessons in Anatomies: A Cultural History of the Human Body (Norton) by Hugh Aldersey-Williams. An English journalist whose most recent book was Periodic Tales, about the elements, Aldersey-Williams has lightly inserted himself into anatomical arenas. You'd expect him to get to anatomy labs, of course, but he also tries ballet, participates in a drawing class featuring nude models, gets an MRI scan of his brain, visits a tattoo parlor, and donates a pint of blood. The result is a series of essays in chapters ranging generally from head to toe, and though each chapter ranges wide and takes in anecdotes and literary references, there is an enormous amount of science here, packed within an agreeably chatty and humorous style.
In his introduction, the author bemoans his lack of biological education, made newly apparent when he realizes his bladder isn't working the way it used to nocturnally. This started him researching the "elasticated bag made of thin layers of muscle," research which flowered eventually into this book. A series of visits with consultants reveals the surprising cause that the kidneys produce more urine during sleep as they get older. That is a simple explanation, but the nightly results of the fuller bladder are complicated. You can consciously feel when you need to urinate, but not when you are asleep. Your body is conflicted; it wants you to sleep, but it also wants your sleeping place to stay dry. It isn't just that the bladder's stretch sensors send a signal to the brain to do something about the increasing fullness. They do, of course, but first, the brain, having gotten the signal, does a confirmation routine: it signals the bladder to contract a little, thus gauging whether it is really full and whether sleep needs really to be interrupted. The bladder resignals; maybe it can go a little longer, or maybe it really is time to get up. "All this happens in your sleep, and saves your being awoken until you really need to be. It's like the snooze button on an alarm clock."
Central to this book's thought is Rembrandt's famous painting, The Anatomy Lesson of Dr. Nicolaes Tulp of 1632, showing eight anatomists in their white collars, crowding around the body on the slab. We know the body to be that of Adriaen Adriaenszoon, hung for theft an hour before the scene in the painting. Aldersey-Williams explains that criminals were cut up for research as an extra postmortem punishment, and that if the threat of the gallows was not enough to make you behave, perhaps the prospect of being cut up and denied any sort of burial might do so. (It is one of the admirable advances of humanity that superstition plays a lesser role now, and a major source of cadavers for anatomical study is the bodies of people who have willed them to research, realizing that the body will be of no use otherwise.) Rembrandt posed the group as if they were involved in a real dissection, but Aldersey-Williams points out that a real dissection would not be performed this way. Dr. Tulp has dissected Adriaenszoon's left arm but left everything else intact; that was not the way a dissection was done, because for the sake of the doctors around the table (and the audience in the theater, who may have paid for the show), the abdomen was always opened first, with the most smelly parts revealed and then removed from the scene. Rembrandt probably painted in an arm that had already been dissected, but he got it wrong - the muscles are attached to the wrong side of the elbow. In the picture, though, Dr. Tulp is with the instrument in his right hand pulling on the muscles that work our fingers just so, in a gesture he makes with his left hand, a demonstration and a reminder that our fingers work independently and in union with our thumbs, a unique facet of human hands.
At around the time Dr. Tulp was anatomizing, Shakespeare was writing, often about innards, references that Aldersey-Williams says are a response to the anatomical understandings of the times by providing fresh images and metaphors. There are, for instance, 1,047 occurrences of the word "heart" in the plays, with King Lear having the highest count, not Romeo and Juliet. You'd expect Shakespeare to use plenty of words denoting heads, eyes, and hands, but there are also 82 brains, 44 stomachs, 37 bellies, 29 spleens, and so on, down to 1 kidney. When Hamlet meditates on "this mortal coil," Shakespeare was relying on multiple meanings of the word at the time. The word meant turmoil or trouble or a heap, and just at the time Shakespeare was writing it was coming to mean a stack of loops, something like the human intestines, with which Aldersey-Williams shows Hamlet was preoccupied. The author does not draw on just Shakespeare, but Pliny the Elder, Rubens, Descartes, Dickens, and more.
In our attempts to understand anatomical workings there have been blind alleys. One of them was phrenology, which Aldersey-Williams traces from the revolutionary ideas of Franz Joseph Gall. In the eighteenth century, Gall correctly understood that the brain was made up of different regions that did different things, but he ascribed to particular regions such behaviors as vanity or kindness. He may have had trouble advancing his theory because he granted religious feeling to just another area of the brain, rather than suffusing the whole. His acolyte Johann Spurzheim fell out with Gall, relabeled and increased the "organs" of the brain, and promoted the idea that the prominence of an organ such as combativeness or amativeness could be felt from outside the skull. Phrenology was more than a fad, and it had serious adherents, and journals, societies, and conferences. It lasted far longer than it should have, and the many little statues of heads with named regions are still familiar bric-a-brac. An interesting phrenological mistake: practitioners had located the brain's visual faculties right behind the eye, where sensibly they ought to be. Our brains evolved, and were not designed in a sensible way, however; the visual processing areas are way to the back of the head, far from the eye.
As if human anatomy is not enough, Aldersey-Williams delves also into angelic anatomy. Angels have wings to enable them to flit swiftly from place to place. Of course, as miraculous beings, they would need no such bodily hardware, but artists show angels with wings of birds. (A demon might have wings of a bat, which humans somehow think better represents evil than a bird does. I cannot remember an angel or a demon being equipped with the wings of an insect, which would do just as well.) But wings on angels "fail every practical test because the artists never augment the bone and muscle in a way that makes physiological sense."
We cannot grow angel wings, but perhaps we can make other extensions. A performance artist named Stelarc has had surgeons install an ear onto his arm, an ear made of a polymer scaffold over which extra skin was grafted. It has a microphone in it, and a Bluetooth connection. In a final chapter, Aldersey-Williams considers why we have an enthusiasm, and a fear, for robots that accurately mimic human bodies (although there is no need for robots to have anything but a robot form, whatever that might be). Immortalists are claiming that it will not be long before human life span will be pushed to a thousand years, and transhumanists assert that human consciousness can be uploaded into some electronic cloud. Even if such plans were possible, they seem hardly desirable. We had best appreciate the more or less three score and ten years we get, and the wondrous machinery that makes the decades roll bodily by. Anatomies is perfect for fostering that appreciation.