What does the appendix do? - and will I miss it once it's out?

Well, those are both good questions, and the short answers are : "No one knows for sure," and "No."

If that satisfies you, then click here to go back to the museum guide.

If not, then read on, gentle visitor.

What does the appendix do?

leonardo appendix

As you may remember from the anatomy and physiology page, the appendix is an extension of bowel that creates an eddy , or sump, off the first portion of the colon. Stool is mixed in the distensable well of the cecum before being pushed on. Some of the stool may pass into the appendix, but appendiceal peristalsis pushes it back into the colon. The appendix also makes mucous and antibodies which are also pushed into the cecum by peristalsis.

Sump Phenomena

Sumps are very interesting phenomena. One normally thinks of a sump in terms of a pit in the basement to collect groundwater before pumping the water out of the house. They really are any low lying place off of the main stream of water.

The word "sump" is derived from the German, Sumpf,or swamp, and a swamp, or a marsh, is a naturally occurring sump in that it is a low lying land off the river.

As one may observe from a marsh, still water, a lack of currents and eddies allows for a different ecosystem than in the main stream. Bacteria and other creatures have the opportunity to grow - consider the murky water of a swamp against the clear water of a brisk stream.

So What does the Appendix Do?

When trying to figure out what something in the body does, I have often found it helpful to look at the organ from an evolutionary standpoint - how would this object or organ contribute to improved survival and enhanced reproduction? A Professor of mine in Saint Louis used to say "imagine a cave man being chased by a sabre toothed tiger? What is going to help him survive?" Well blood clotting is good, a sympathetic nervous system to enhance the heart rate is good; the ability to dilate the eyes to see better is good, and so on.

One of the most common causes of death worldwide, from the time of thesaber-toothed until the present, is dysentery. Cholera is back in the news with a horrific death rate. As anyone (well, really everyone) who has ever had food poisoning and diarrhea will testify, it is very easy to ingest an agent that quickly overwhelms the GI protective mechanisms.

cholera cot


The diarrhea of cholera is so profound that it is often referred to as "rice water stools" and the volume and quick weakening it causes from dehydration led to the invention of the "colera cot" which is basically a cot with a hole cut in it and a pan underneath to collect the effluviam.

So, suppose a person had a sump in the bowel, a place where beneficial bacteria and helpful antibodies could reside out of the fecal stream. That sump could serve as a "re-colonization" point for the repopulation of the colon - remember the flora of the gut exist as a balance of beneficial bacteria, a micro-ecosystem if you will.



In 2008 Randal Bollinger and others at Duke University proposed that the appendix exists as a "safe house" for beneficial bacteria that reside in an eddy of the mucous biofilm that lines the gut -

In short, there is a film of mucous that lines the gut and which flows downward with the intestinal stream. This mucous is made by the goblet cells in the Crypts of Langerhans that exist along the length of the gut. Bacteria grow in the mucous biofilm, and, again are swept downstream with the intestinal contents, continually mixed by propulsive peristalsis. The appendix is a sump, or marsh of bacteria laden mucous that sits off the stream. When there is a flood, such as with cholera, the marsh survives, and the bacteria in the appendiceal mucous will repopulate the colon over time.

2/16/2013 Breaking News From the Huffington Post!!

Appendix Evolved Over 30 Times, May Perform Useful Function, Researchers Say

|Posted:02/14/2013 10:33 am EST|Updated:02/15/2013 4:24 pm EST


But it would seem, then, that one would miss the appendix after it has been removed. Well, for Westerners probably not.

For one thing, we live in the most hygeinic age in history. Our food is processed and sterilized. We no longer have worms or huge epidemics of dysentery. Cholera is rare, and so there is no large numbers of people, with and without there appendix, to study in acute diarrhea.

Except for clostridiumdifficult (c. diff.) outbreaks. We have selected out "superbugs" with the indiscriminate use of antibiotics. One is the bug that causes diarrhea, sometimes death, after use of antibiotics. There are two reports of an increased frequency of retaining this bad bug, of not repopulating with good bacteria, after an acute diarrhea with c. diff. if someone has had their appendix removed. The numbers are still to small, and no one has ever reported that people who have had appendectomy are more susceptible to diarrhea.

In the 1980's there were a few reports of an increased risk of colon cancer in people who had undergone appendectomy. These results were never duplicated, and the study sizes were too small to draw any meaningful conclusions.