I have a neat medical trick you can try at home. You will need to take off your shirt, and have a mirror and a marking pen at the ready. What you are first looking for is your hipbone. If you are an old fart like me, with 60 some years of subcutaneous fat accumulated, gently press in at your waist (or a reasonable approximation thereof) until you find it. The top of your hip is your illiac crest, and the most forward part of that is your anterior superior illiac crest. Mark this with a dot. Now find your belly button, which should be higher and dead center in your abdomen. Mark that with a dot, and try not to giggle while doing so. Now connect the dots with a straight line. Two thirds of the way down that line from your belly button is your McBurney's Point. And beneath your McBurney's Point is your appendix. Ta Da!
This magical location was discovered by Dr. Charles Herber McBurney (above),. And because he was a surgeon, Dr. McBurney's only interest in the appendix was when he wanted to cut it out. This was not easy, because between your magic marker and your appendix are your abdominal muscles. Slicing willy-nilly through these could make it very hard to continue breathing, which is very bad. But then if your appendix bursts open, that is also very bad. It was Dr. McBurney who developed the life saving operation called an appendectomy, where an appendix is safely removed. The procedure has become so standard that some people have their appendix taken out in advance, even though only 10% of the population develops appendicitis. “Better safe than sorry” is their motto. However the second most important motto in medicine should always be, “Not so fast.”
The proper name for this 4 inch long unprepossessing organ is the vermiform appendix, which means “a worm-shaped addition” (center), and humans aren't the only creatures with one. The 50 or so euarchontoglires which share this structure are both mammals and marsupials, including rodents, opossums, rabbits. wombats, tree shrews, flying lemurs, monkeys and humans. Most of them are vegetarians, which has inspired human vegetarians to celebrate the appendix as a vestige of their vegetarian ancestors. Unfortunately, it turns out, it isn't. In true vegetarians the appendix is a large organ, used to digest cellulose. In humans it's so small it seems like an after thought, an appendix to the main human story.
The human appendix juts out from the junction of the large and the small intestine. But unlike its neighbors the human appendix is just an empty sack that leads no where, inspiring Mark Twain to observe, “Its sole interest is to lie and wait for stray grape-seeds and breed trouble.” The trouble arrives with an infection, when the appendix swells up and bursts, spilling nasty bacteria all over your nice clean abdominal cavity. If you have a fever and are feeling a pain in your middle, find your McBurney's point and press down with one finger. If that causes excruciating pain, you are the unfortunate owner of a burst appendix, and you have a few hours to have it removed and your system flushed with antibiotics. Other wise, you are dead.
So here is this small, squishy sack, not much bigger than your index finger, that isn't connected to anything but your intestines, doesn't seem to produce anything, and you don't seem to miss it much when it's gone and occasionally it tries to kill you. Humans can be forgiving for thinking it was pretty much useless, like the last three vertebrae of your spine, all that is left of our once magnificent prehensile tails, reduced in modern humans to balancing you upright when your sitting on your butt. What good is an appendix?. For the last hundred years, the opinion of the medical community was almost universal, echoed by the authors of the medical textbook, “The Vertebrate Body”, “Its major importance would appear to be financial support of the surgical profession.”: written like a true diagnostician.
There is one hint about what the appendix might be doing, in that when you look at it in place it doesn't look like its neighbors, even when inflamed and surrounded by puss (above). Where the intestines are various shades of red, pink and purple, the appendix is white, and this is because it is made up of lymphatic tissue, Latin for “connected to water”. The most common member of this variety of cells, lymphocytes, are known as white blood cells . Their job is to identify invaders floating in our blood stream, and swallow them. So any lymphatic tissue, like that found in the appendix, must be concerned with defense: right?. But the appendix has only a tiny opening connecting it with the intestines, and a healthy appendix contains no bacteria that are not also present in the intestines. What could it be doing, if anything?
Well, it must be doing something, since the latest evolutionary genetic research indicates it has been invented 30 separate times in the euarchontoglires. And then about a decade ago it was discovered that lymphocytes also raise the “PH” level in your intestines, thus encouraging the 700 or so different species of “friendly” bacteria that we require to digest our food.
See, the healthy human gut is acidic - the small intestines have a PH factor of 6.8. This will not burn through steel, but the 10 trillion Prevotella, Bacteroides and Ruminococcus bacteria (amongst others) in your gut, require that acidity to thrive. They break the proteins and sugars that pass through your intestines into smaller molecules, and those are then filtered into the blood stream. An invasion of “bad bugs” reduces the acid level. That's why those bugs are bad. And you know the bad bugs outnumber the good ones in your gut when you get diarrhea. In other words you are not what you eat, but what you digest. Now, eventually your lymphocytes will eat the invaders in your blood stream, and the diarrhea will flush them out of your intestines. But how do you replace the good bugs in your intestines?
Well, according to Pediatrician Indi Trehan, at Washington University in St. Louis, that's where the lowly appendix comes into play. “The appendix has a unique anatomical location that is out of the way. Bacteria can be kept safe there for repopulating as needed,” he says. In other words, the appendix is a biological panic room. It keeps the good guys nice and safe, warm and happy, acidic and reproductive, even when your waiter forgets to wash his hands, or the tuna fish in the refrigerator goes bad, or the three bean salad is left out on the picnic table in the sun. It is in fact a validation of the theory of evolution- the use of available material to preform new functions.
Charles Darwin thought the appendix was vestigial, like your tail bone. He was wrong. Given the information available to us, he would have realized he was wrong. But its role as a panic room in the gut, and its constructed from cells that had been evolved for other uses, and that it was re-invented over and over in species with and without placentas, (mammals and marsupials) is proof of his fundamental idea of evolution. And so are the 10 trillion bacteria in your gut at this moment happily chomping away at your food, just like the bacteria in the gut of every living thing, from mosquitoes to elephants, even those without an appendix. .
This new view of the human vermiform appendix as a panic room, has supported a rethinking of Dr. McBurney's approach to an inflamed appendix. Increasingly patients are being admitted to hospitals, not for surgery, but for a heavy course of IV antibiotics. And as long as the appendix has not yet burst, usually, this works. It is cheaper and safer for the patient, and easier on the doctors, as it cuts down (pardon the pun) on panic surgeries. And it also makes the 10% of Christian Scientist with appendicitis, happier as well.
I'm not sure what the “homeschooled” fundamentalist Christian children will do about all of this, the next time one of them has a pain in their gut. If, to quote Georgia Congressman Paul Broun, who is a medical doctor, the theory of evolution is a lie, “straight from the pit of hell”, then why would an IV course of antibiotics calm an inflamed appendix, irregardless of the state of grace of the owner of the appendix or the doctors, or the nurse who hangs the IV bag? I've said it before and I wll say it again here; belief in an almighty God does not require stupidity, no matter how many stupid people say otherwise. Evidently it doesn't hurt, but that is hardly a ringing eendorsement.
- 30 -
No comments:
Post a Comment
Please share your reaction.