We're pretty used to considering our bodies to be our property.
You're born with this body. You can feed it and exercise it and clothe it, however you like.
You can make it smarter, or dumber, in any way you see fit.
Because this is MY body, right?
Well, yeah.
Technically, I mean, you own your body the way that you own your house,
except that you can't sell it. At least, legally.
But it turns out you are not the only resident of your body.
Let's just say... that you have some tenants.
And like all tenants, there are some that, you know, mow the lawn, and shovel the sidewalks,
and fix the leaky sinks for you.
And then you have the ones who are cooking meth in the bonus room
and blowing up your garage with fireworks.
So welcome to this video! It's all about the stuff that lives inside you.
Look on the bright side though, if you Googled human parasites,
you'd see all kinds of pictures that you do not want to see,
so this is much better a way of being introduced to the topic.
So consider it a gift from me; I'm going to tell you all the stuff that you need to know without telling you about
much of the stuff that you really don't want to know about, probably isn't going to happen to you anyway.
Namely, the [BEEP] being [BEEP], noses and [BEEP] and [BEEP] that they [BEEP].
These are things I've seen, you guys!
And they can't be unseen.
So parasite, it's a strong word.
Technically, a parasite is any organism that makes its living off of another organism,
sometimes they're bad, and sometimes they're not.
Parasitism is a pretty clever strategy, they just sorta sneak in, they set up camp inside of a body,
and then they can devour it from the inside out.
Or they might not do any significant harm at all, or
they might even help their host animal.
There are many animals living inside of me right now that are actually helping me live a happy, healthy life,
and, there are also a bunch that I just don't notice, and are completely unobtrusive.
So I'm going to talk about these good guys first,
and then a little later on I'm going to scare the adenoids out of your face by talking about those
supervillain parasites that you do not want.
So animals that live, you know, inside another animal but actually help them,
those are called mutualistic, symbiotic relationships.
And that's roughly the relationship that we have with the 100 trillion microbes that are living inside of us at any given moment.
So 100 trillion... hard to really wrap your mind around that number.
As scale, number of cells that you have, with your DNA in them, in your body: about 10 trillion
I'm going to say this again for you, there are ten times more bacteria cells in your body than you cells.
Do your best not to let this freak you out, because those are really really important little animals living in you,
and they make you life way better.
Some scientists are going so far as to call this the human microbiome.
We're our own biome!
So much so, that some scientists go so far as to name this human microbiome,
that is, the ecosystem of animals that lives inside of us, our forgotten organ.
So, what are these things doing to earn their keep?
Well, I'm glad you asked that!
They kill harmful bacteria in our noses, they form a protective coating on our skin,
and the vast majority of them live in our intestines, doing really useful stuff,
like helping us break down the food we can't digest by ourselves,
making vitamins biologically available to us,
teaching our immune systems not to freak the frick out over stuff that doesn't matter,
and killing off the harmful bacteria that often find their way into our guts.
Without them, our lives would be miserable, and I'm not going to tell you how miserable,
I'm just going to say that adult diapers would be involved.
They are so important that doctors are now diagnosing people with bad gut bacteria
and they're putting good gut bacteria in to the people
through what's called fecal transplants, which is exactly what it sounds like.
I talk about it more in my obesity video.
But not all of the animals that live inside us are super good awesome animals.
Some of them are just meh.
We provide a lot of food and transportation and lodging for a lot of animals to do absolutely nothing to us.
This is called commensal symbiosis, when one of the participants benefits
and the other one - it doesn't care.
An example of this being the eyelash mite or follicle mite, that basically lives anywhere that there'e hair on your face.
Basically, these tiny little arthropods just hang on to the base of your hair follicle
and eat the oils that are excreted by your sebaceous glands
and that might seem gross and sort of not cool to you,
but it's not really affecting you in any way, so I suggest you just deal with it.
Besides, you're gonna have to save your big freak-out guns for where we're headed to right now.
Be advised - the rest of this video is moderately gross
and may not be suitable for all audiences.
Especially those who suffer from delusional parasitosis,
which, by the way, is a real thing.
Objectively, parasites are pretty awesome.
I mean, they are tiny, generally, but they're scheming and they're clever
and they can take down an animal much much much much much much bigger than it.
Parasites that feed on humans, the bad sort of parasites, can be organized into a few different groups.
We have the protozoans, the worms, the crawly bugs, and, category number 4, freaky stuff.
So lets start with the protozoans.
Now, protozoa, which you may have heard of, are one celled organisms.
A lot of which can kind of like move around on their own
and get into their host through drinking contaminated water,
or through the saliva of a tick or a mosquito, that bites you etc.
And once these bad guys are in your gut or you blood or whatever their single mission is to take you down.
Take, for instance, neagleria fowleri, also known as the "brain eating amoeba."
This guy is found in bodies of fresh water, that stay pretty warm all year.
And this is why I live in Montana.
So basically, this little guy spots you swimming around in some tepid lake or river somewhere
and crawls over to you and wiggles it's way right up your nose.
From there it works up to the olfactory bulbs of your forebrain and starts to feed on your nerve tissue.
And then your brain starts to swell up and then, 98% of the time, you die.
In 2011 two people died, because they were using contaminated water
to irrigate their sinuses with neti pots.
So always remember to boil your neti pot water.
Especially if you live in Louisiana.
Anyway there are a bunch of other diseases, that you have probably heard of,
that are caused by a parasitic amoeba.
African sleeping sickness, giardia, malaria, toxoplasmosis.
And this brings us to the second type of parasite:
the worms, which are arguably the worst.
This are the ones, which I highly recommend you DO NOT GOOGLE.
Because parasitic worms are in it to win it.
And when I say win it I mean breed so many worms, that they fill your whole body up
and start coming out your nose or your butt.
So good news!
If you live in a developed world and you have like power outlets and hot water and an internet connection
you probably don't have any chance of getting any of those worms.
But many people in the developing world have to deal with these kinds of things every single day,
because they don't have access to clean food and water like we do.
They're more likely, because of lack of plumbing, to be in more contact with human feces
and they live in a part of the world where a mosquito bite can lead to elephantiasis.
Ah yes, elephantiasis, or lymphatic filariasis, an infectious tropical disease
caused by parasitic roundworms, that are passed from person to person through mosquitos.
So worms can cause unbelievably horrifying amounts of swelling in the legs, arms, breasts and genitals of their victims.
Elephantiasis, it turns out, is one of the leading causes of disability worldwide.
So the next type of parasite, of course, is the crawly bugs,
which is my classification for parasites that feed on you from the outside,
like your bed bugs or your scabies or your body lice or your genital crabs, that kind of thing.
Now in my opinion these things are way better than worms or the protozoa,
because they're just way less likely to kill you, but they are pretty gross.
In fact, just talking about them makes me feel like there's things crawling on me
and this is where the word delusional parasitosis comes in.
That disease which has nothing to do with parasites, except that you think you have them,
because you've been hearing about them and it makes your skin crawl.
And finally we have number 4, our last category of parasites - the freaky ones.
And there are lots of other kinds of parasites as well of course,
like the bot fly, which lays it's eggs under your skin where they hatch
and then feed on you until they're ready to, uh, erupt, as it were.
And then there's the candiru, a tiny parasitic catfish that lives in the Amazon river and loves the smell of urine.
If you're in the Amazon river and peeing, which I suggest you do not do,
the candiru may sniff you out, swim up your urethra and camp out there until it is surgically removed.
*groans*
And these, my friends, are the tenants of your body.
And I hope that you have them, the good ones at least.
And the bad ones, well, let's just get them away from us.
Congratulations on becoming a smarter person.
There are citations for this episode in the description,
if you would like to have them and read more about this.
I question why you would want to, but it's very interesting.
You can as always connect with us on Facebook and Twitter,
ask us questions, suggest topics for us and of course down in the YouTube comments below.