The other hypothesis that doesn't seem like it's quite as plausible these days has to do with an old idea called the hygiene hypothesis. So one hypothesis is that, with the lower fiber content, we're more likely to get little pieces of food that's being digested stuck the appendix and cut off blood supply and cause this inflammation. So the appendix is kind of helping us in two ways, both within the gut: It's helping to fight off invading pathogens, but also to repopulate the gut with this beneficial bacteria after gastrointestinal issues.Īppendicitis is predominantly happening in the industrialized nations of the world - areas where fiber content of the diet tends to be lower. The idea is it's safe during this time of gastrointestinal distress and it can then exit the appendix and recolonize this good bacteria throughout the rest of the gut. And they argued that the appendix may serve as a safe reservoir for the beneficial gut bacteria that we have.ĭuring times of gastrointestinal distress - you know, a diarrhea episode where all of your good gut bacteria is getting kind of flushed out of the system - the appendix is kind of this blind tube with a very narrow diameter and narrow lumen, so the good bacteria doesn't get flushed out of the appendix. So this was a hypothesis that was put forward by a team from Duke University in 2007. The second function that it serves is what we refer to as the safe house. The appendix has a high concentration of immune tissue, so it's acting to help the immune system fight any bad things in the gut. The first function is supporting the immune system. It turns out that the appendix appears to have two related functions. So what are the appendix's beneficial roles? It's unlikely that the same type of structure would keep appearing if it wasn't serving some beneficial role. So that is evidence that it must serve some adaptive function. It has appeared independently multiple times throughout mammalian evolution. If you map the distribution of appendices across a phylogeny - a tree of mammal life - you can interpret that the appendix has actually evolved independently. And so Darwin's interpretation of it as a vestige was reasonable at the time, given the information that he had.īut now with modern technology, we can see things like the microanatomy and the biofilms in the appendix, and we have a better understanding of what it is and what it's doing. The that we can live without it does provide some support for the idea that it's vestigial and it doesn't really do anything. There had been a lot of discussion about what the appendix might do as a function, whether it served a function, prior to Darwin's time. How did scientists get the idea that the appendix was useless? So if you draw a line between your bellybutton and the part of your pelvis that sticks out, two thirds of the way down, that's about where the appendix is. You can identify the location based on a landmark called McBurney's point. It's about the size of your pinky finger, and it projects off the cecum, which is the first part of the large intestine. The type of appendix that humans and some primates and rodents have looks like a little worm. This conversation has been edited for length and clarity. NPR's Short Wavespoke to Smith about what the appendix is good for and how a future where appendicitis can be prevented or treated without emergency surgery could be on the way. "But it turns out recent research shows it does have functions that can help us," she says. She acknowledges that the appendix has a bad rap as a useless organ that can cause you pain and require emergency surgery. And all these decades later, Smith has made a mark in the field by studying the very organ that threw off her family's vacation plans in 1992. Smith grew up to be a professor of anatomy at Midwestern University and editor-in-chief of a journal called The Anatomical Record. "It inspired me to wonder: Why do we have this weird little organ in the first place? What does it do? Why does it get inflamed?" And after the surgery, she found herself intrigued by the part of her body she had so suddenly lost. Smith still has a small scar from the appendectomy.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |