New ideas about the human body

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Part of Panorama

Title: New ideas about the human body
Language: English
Source: Panorama XX (6) June 1968
Year: 1968
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Fulltext: This is a very informative and important article about the human body as a as a chemical apparatus. NEW IDEAS ABOUT Over the centuries, man, when contemplating his own body, has alternately gained and lost conceit. Once he was inclined to think of him self as one of the lords of creation, ranking just a lit tle lower than a god. When he began to compare him self carefully with other liv ing creatures, he reluctantly came to the conclusion that he was a close relative of the ape. Gradually, in the light of modern science, man has come to look upon his body variously as an energy-andheat‘ producing engine, as a chemical plant and as an electronic apparatus. Let us examine the vali dity of these conceptions. Obviously, there are many resemblances between the human body and an engine. What is food but fuel, and what is the intestinal tract but the furnace of a living boiler? To be sure, man has no visible cylinders and no machine and also THE HUMAN BODY pumping pistons, but the ex perimental evidence indicates that food is converted into energy just as coal or wood is. The heat value of food is even measurable in calo ries, like the heat value of any other fuel. An ounce of sugar “burn ed” in the body yields just as much heat (or energy) as it does when buried in a suitably constructed oven. A steam-power plant has its fuel storage bins; so has the body — it stores sugar and other fuel in the muscles and the liver. The machine-like nature of man is especially striking when an analogy is made with the internal combus tion engine. In the body, food is turned into sugar and the sugar into alcohol, where upon the alcohol is exploded in the muscle cells. There are millions upon millions of cells, and the charge of alcohol received by each of them is infini 12 Panorama tesimal — so we do not hear the explosions. But the hu man engine is chugging just the same, and at almost the same rate of efficiency as the non-huinan. In fact, one scientist has found that a good Yale crew and a good internal combustion engine both have an efficiency rating of about 23 percent. Engineers can push the machine analogy even fur ther. They see ball-and-soc ket joints where the arms meet the shoulder and where the thighbones meet the pel vis; they see powerful crun ching. levers in the jaws, a fairly good pivot where the skull sits atop the spine, muscles ingeniously contrived so .that they can both push .and pull. There is no ques tion ' that - the lungs are bel lows, though they oxygenate the blood and blow on fire. And there is no question that the heart beats 2,500 million times without failure or repair. And what can be more mechanized than artificial organs doing outside the body what the lungs, kidneys and heart do inside? One scientist cultivates human marrow outside the body by means of an apparatus which serves as a lung, a kidney and a circulating system. Artificial kidneys have been devised to cleanse the blood of wastes which di seased kidneys cannot re move. Weary human hearts have been rested while ex ternal mechanical hearts cir culated the body’s blood (sometimes with the aid of artificial lungs). Even the laws of. hydrau lics are applicable to the body — up to a point. The 10 pints of bl odd that the heart keeps in circulation (additional blood is held in reserve in the liver, the spleen and other organs) is a stream which, like other liquids in motion, obeys ri gid physical principles. This stream is a river of life, in the sense that, if we drain it off, we die; it is also a sewer, in the sense that it carries poisonous wastes to the kidneys to be disposed of. But this is one of the points at which the compa rison between the human bo dy and a machine begins to exhibit its limitations. Let us assume that into the hy draulic contrivance which is June 1968 13 the blood stream we inject a foreign substance — a se rum, or a vaccine. What happens? No laws of me chanics provide an answer; we must go to chemistry. What happens is that, with amazing swiftness, antibodies are marshaled to destroy the invaders. A battle is waged. The weapons are chemical weapons. Thus, one Kind of antibody, called opsonin, makes invading bacteria taste good, whereupon the transformed bac^ena are de voured by dements of the blood called phagocytes. Another chemical, agglutinin, causes the bacteria to clump so that they can be devoured in wholesale Hl; As a hydraulic machine, the blood stream will stand muoh tampering, but there are . definite physical and chemical limits beyond which this tampering cannot go. Overheat the blood and you rave; chill it and you become blissfully indifferent even to death. Take away its oxy gen, and the mind loses its reasoning power. Decrease its calcium by half, and con vulsions result — followed by coma and death. Double the calcium, and the blood thickens so that it can hard ly flow. But if we compare the hu man body to a furnace, we find that the laws of ther modynamics are not fully applicable. Heat is like wa ter in that, when a hot mass cools, it falls from a high to a low place — i.e., the temperature level changes. In a machine, the bigger the drop in heat or water level, the more energy released and work done. But the healthy body works in another way. Its temperature always remains at around 9^.6° F., no matter how much beefsteak or how many potatoes we put away. We expend more calories to fell a tree than to perform ordinary office work, yet our temperature is kept constant by the well regulated evapo ration of water from the skin. A major flaw in the con cept of man as a machine began to be apparent with the discovery of vitamins and their functions. When it was found that a table might groan with food while the men who ate it could nonetheless be starving to death — that is, succumbing 14 Panorama to such deficiency diseases as pellagra and scurvy — it was clear enough that the human organism was some thing more than an energy producing engine. It was also a chemical system in extremely delicate balance — a balance that could be up set by the daily lack of no more than enough vital sub stance to cover a pinhead. Now this chemical-balance concept is being strongly for tified and extended by dis coveries about hormones and the functioning of the glands which produce them. Some of the most impor tant work in this fiel'd as been done by Dr. Hans Selye of the University of Mont real. Convinced that all dis ease is the result of some thing that impinges on the body from outside and thus upsets the internal balance. Dr. Selye has subjected thou sands of rats to the kinds of assault that human beings must endure — worry, fright, overwork, poisoning, chilling to the freezing point. Autop sies on the rats have always revealed damage to the ad renal glands. The adrenals bear the brunt of any assault from the outside because they are chiefly responsible for main taining the body’s chemical, balance. They keep sugar and salt at the proper level. Their cortex, or “bark,” se cretes some 20 chemicals which are the body’s princi pal defenders. One is cor tisone. Thus it is easy to see why doctors have been able to achieve such startling results when they administer corti sone to sufferers from va rious degenerative diseases. When the body’s adrenal glands .have stopped provid ing adequate supplies of cor tisone, but it is supplied from outside, the delicate ba lance of body chemistry is restored. With ACTH it is the same. ACTH is obtained from the pituitary, which lies in the middle of the head and con trols all the other glands. The adrenals, which lie over the kidneys, obey the com mands of the anterior lobe of the pituitary — the same lobe which supplies ACTH. When the pituitary is re moved or disabled, the adre nals shrivel. Transplant a new pituitary — or admi June 1968 15 nister ACTH — and the ad renals come to life again. Taking the hormone func tions into account, we must modify our conception of man as a machine even more. The body is a chemical whole of incredibly fine balance; moreover, it possesses the amazing ability to repair it self, which is more than can be said of any machine. When the body ceases to be able to repair itself, it must get help from outside. But whether the job is done from outside or inside, it is large ly done with chemicals, of which the most potent are minerals, vitamins and hor mones. Those who are engineminded and hate to give up the machine analogy may cogently argue that these chemicals- do no more than those which are added to gasoline to prevent automo bile engines from “knock ing.” After all, what are the symptoms of disease but palpable knockings? They may also point to the re cent development of electro nic computers — contrivan ces which, employing as ma ny as 2,000 vacuum tubes (just like those in radio sets), can solve in a few minutes problems which would keep a mathematician busy for months. All in all, these machines behave in a very common way; they not only do something which closely corresponds to “think ing,” but they have memo ries and they throw tantrums. Manifestly, the conception of man as a machine will never die completely. Nor, for that matter, should it, for it is a most convenient way of explaining what hap pens when, for example, we drive a nail or write a let ter. Physical anthropologists, anatomists and most evolu tionists are now aware of the obvious deficiencies of the machine theory but, for the sake of convenience, they are likely to keep on think ing of the human body m machine terms. A curious thing is that, when they do think in these terms, they are inclined to hold the body up to scorn. They say it is badly design ed to perform some of its most important functions. In an evolutionary sense, it is built of second-hand parts, 16 Panorama parts which should have been junked long ago. The trouble began, it seems, when man, in the course of evolution, first stood on his hind legs. As a result of standing, his in testines have sagged, which accounts for the commonness of hernias. An engineer cer tainly would not have put the whole weight of the body on the curved back and on two inadequate feet, nor would he have made the heart strain itself by pump ing blood vertically against gravity. It must be admitted that the engineering of man is not all that it might be, and that the human body con tains many obsolete devices. The reason is that when a living organism starts evolv ing, ‘ old parts may degene rate, but they are not en tirely discarded. New ones are added to the old, or superimposed. In the corners of our eyes, for instance, we have the remnant of an ex tra eyelid. In the top of the head is buried the pineal gland — a rudimentary ^third eye. And then there is the famous vermiform appendix, an entirely useless part which should have been scrapped long ago. The brain is a good exam ple of the way nature piles up second-hand parts and superimposes new ones. Ac tually, we have a dozen brains, bequests of our re mote ancestors. Only the great forebrain with which we do our think ing and the highly convo luted cortex of the cerebrum are relatively new. And nobody has yet found out exactly how all this rather unsightly mass of gray mat ter works. This much is certain: The brain is an electro-chemical contrivance and neither an engine nor an entirely automatic com puter. No combination of mechanical parts and elec tronic tubes will ever dupli cate its acts of creation. But isn’t it probable that the brain will develop still further and that man’s men tal powers will improve? No species of animal is so unstable as man; a score of different types of human be ings have come and gone. There is no reason to sup pose that we are the last word in machines or nicely balanced electro-chemical June 1968 17 systems. Probably we are only preliminary sketches, hints of something better to come. If this is the case, it may tak,e another 500,000 years to produce our superhuman successor. He will probably be free from our sinus trou bles, our appendicitis, our hernias, our weak backs, our fallen arches. He conceiv ably could have a brain 25 percent larger than ours. Sir Arthur Keith bids us look at present-day woman if we would have a preview of the new-model human be ing. “The smooth-browed condition is already achieved by the female of our spe cies,” he says. “We poor males have lagged behind our wives” Men still have the over-hanging brows of Pe king. Man, Rhodesian Man and Neanderthal Man, al though by now it is greatly reduced. In this respect, Sir Arthur believes that wo men are about half a mil lion years ahead of men. The man of the future will probably have a small, re ceding face, because power ful jaws and powerful chew ing muscles are no longer necessary. He will prob ably have one less lumbar vertebra than we have, so that his weight will be bet ter distributed. No doubt there will be corresponding changes in the pelvis. Hands are likely to remain as they are, but our feet, with their arches that tend to fall and their almost useless little toes, are destined to ; be greatly improved. On the eventual appearance of such mecha nical refinements, most. phy sical anthropologists and evo lutionists are agreed. Here prediction must end, because man is more than a machine. What his electro chemical future may be no one can even divine. And his evolutionary future de pends more on electro-che mistry than it does on me chanics. Above all it de pends on his hormones. If some of his 20-odd ductless glands mutate, there is no telling what may happen. A more active pituitary would make a giant of him, a more active thyroid would make him more energetic and restless, and more active adrenals would alter his emo tional life. It is evident that if we cannot make up our minds 18 Panorama about man — whether he is a machine or a piece of chemical apparatus — it is because scientists have not yet succeeded in telling us what life it. If we knew what life is we could tell better what kind of a contri vance man is. — By Waldemar Kaempffert in N. Y. Times, Sept. 10, 1950 maga zine (copdpnsed). AN EXPLANATION Do you ever try to give explanations? Do you ever listen to explanations? Some people are always trying to explain things — why they’re late, why they forgot, why they failed, etc. Too much “explaining” is often an “alibi.” But many times, the explainers are just wast ing their time and their breath. Why? There gre other people who simply do not listen to ex planations. When these “other people” are one’s boss or best friend, or wife or husband or children, then you can really have a situation on your hands. One of the biggest mistakes that we can make as human beings, I think, is to deliberately cut ourselves off from other human beings — by re fusing to listen to the explanations of others. How quickly, how easily, how definitely we just clamp our hands over our ears and shout: “No, I don’t want to hear any explanations.” What a tragedy — this is how so many former good friends today find themselves so lonely, yes, even in the very midst of the so-called “population explosion” with its dire predictions for the future. — by Paul Sheehan in Philippines Herald. June 1968 19
pages: 12-19