the

Your Appendix Isn't Useless, After All

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run your business the appendix gets a

bad rap you probably never even think

about it unless it's the reason you're

doubled over in abdominal pain and for

the most part it gets written off as a

useless organ leftover from our

evolutionary past but even though you

can usually ignore it you've got to give

your appendix some credit because it

might not be as useless as you thought

the appendix has evolved in mammals at

least 29 times which is a pretty good

sign that it does something and back in

2016 an international team of

researchers set out to understand why it

appears so many times they started by

looking at what kinds of things animals

with appendices have in common but first

they had to define what in appendix even

is since the thing we call in appendix

comes in all shapes and sizes across

mammals as a starting point the

researchers defined it as a section of

tissue extending from the cecum the

beginning of the large intestine they

then use computer models to analyze data

on hundreds of mammals they gathered

information about their habitats and

social behavior and of course whether or

not they had an appendix and they

concluded two things the first was that

the appendix has evolved more times than

it's been lost so it must have some kind

of evolutionary advantage and second

after finding high concentrations of

lymph tissue which protects the body

against foreign invaders they concluded

that the appendix is involved in

immunity across mammals and that seems

to be the case for humans as well within

the inner layers of the Appendix we find

all kinds of densely packed immune cells

including T and B cells and natural

killer cells which are all important

parts of your body's immune response but

we also find a reservoir of good gut

bacteria hanging out in there it's the

same type of bacteria that lined the

insides of the intestine creating a

protective barrier against invaders

given its prime position just off the

colon researchers think the appendix

might dish out emergency rations of gut

bacteria in times of crisis like during

cases of extreme diarrhea diarrhea can

flush out your intestines but the

appendix may be able to provide a fresh

population of the gut bacteria that

keeps your digestion on track they say

you don't know what you have until it's

gone and it's true one way to appreciate

the immune function of the appendix

see what happens when it comes out to

study published in 2015

found that patients who contracted a

particular bacterial infection called

Clostridium difficile were twice as

likely to develop a severe infection if

they didn't have an appendix that study

alone doesn't prove that the appendix

prevents infection but it does raise

questions about whether or not surgeons

should remove the appendix when they

don't need to since that might actually

cause trouble rather than prevent it

that said appendicitis can be deadly so

if your appendix needs to come out it's

coming out but otherwise maybe we

shouldn't be so quick to dismiss this

organ that's usually just trying to be a

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[Music]