hi my name's ed hope I'm a junior doctor
in the UK and welcome to sick notes my
channel where we look at hospitals human
body and I share some my experiences of
being a doctor that sounds good you can
subscribe and be part of our lovely
community here on YouTube today I'm
going to be continuing my look at the
fantastic show cells at work so this is
episode four okay so this episode is
called food poisoning which is where we
eat some food that's been handled or
stored or prepared badly and it's got
lots of bacteria that's able to grow in
it or maybe some parasites or even some
viruses once they get into our body our
body to text them and kind of what's to
flush the system out so we get lots of
vomiting and lots of diarrhea we've
probably all had some kind of food
poisoning
at some point in our lives I remember
when I had a sort of raw sausage in
Eastern Europe I had a pretty nasty bout
so I'm looking forward to find out
exactly what's happened to my body
during this episode so here we see the
stomach and it's represented kind of
like a volcano with the lava being the
acid which is a really nice analogy
because the whole point of the acid in
the stomach is to kick off the digestion
process and also kill any of these
nasties that might just be in food
normally like some bacteria and viruses
and other things like that but obviously
this acid could potentially damage our
own cells in our body so the stomach has
a specialized sort of layered lining
that we call the gastric mucosa gastric
is just a medical term for anything to
do with the stomach one of these layers
produces a chemical called bicarbonate
which is an alkaline type chemical
therefore will neutralize the acid that
comes close to the lining there for
protecting the cells of the stomach but
still allowing the center point to be
acidic to do its job knowing about the
stomach mucosa is really important
because it can be eroded away with
certain infections and medications as
well and once that's eroded away the
acid will directly attack the cells in
the stomach and will
lead to stomach all served nasty
condition and the rock formation we see
here in the volcano is not by a mistake
because the stomach also has these
ridges so in biology whenever we see
these kind of Ridge like structure it's
for increasing the surface area so in
this example be increasing the surface
area of absorption of the food in the
stomach as well these ridges also enable
the stomach to stretch so when we've
eaten a lot of food the stomach can
stretch up and when the summer isn't
being used it can shred out as well so
this white blood cell has identified a
new germ here the germ is the layman's
term for any disease-causing organism so
it can encompass a virus or bacteria
fungus and parasite as well the medical
term we use is a pathogen path meaning
disease and gen anything that generates
it so pathogen something that causes a
disease and we've met a new white blood
cell here as well I'm not quite sure
what this one is but I guess we'll find
out
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I'm not quite sure what that bacteria
spinning thing was supposed to represent
but our neutrophil has come to the
rescue so this other white blood cell
wasn't as effective as getting this
bacteria so maybe that's a clue as to
what they might be that makes sense that
this cell is in a sinner fill another
white blood cell and that's why it's not
very good at anyway bacteria it's got a
very specialized role it's job is to
deal with parasites or much larger
pathogens than things like bacteria and
viruses they are also really important
in clinical medicine because these are
the cells that react inappropriately to
certain things that give us an allergic
reaction come on huggy cue da so as
pointed out by the neutrophil the
cinephile is there they're very closely
related so it kind of fits in the family
tree we've been developing over these
episodes I'm kind of running out of room
but let me show you quickly so here is
our diagram from before so we have our
stem cell or myeloid progenitor cell
some of the other cells we've met so far
so the red blood cell the megakaryocytes
that produces the platelets we have our
dendritic cell and we have our
macrophage as well and here represents
our neutrophil as we said the assignor
fill is very closely related to all of
these cells but particularly the
neutrophil
so here we have our sinner Phil joining
the family tree
so the acidophiles getting up a little
bit of bullying from the other cells you
know obviously what we talked about
she's not designed to attack this type
of pathogen so just wonder if that's
some kind of foreshadowing in terms of
what her motivation will be when she
overreacts to analogy the fact that she
feels like she's doing a bad job here so
when she sees something she had an
inappropriate like allergic reaction I
wonder if that's gonna be so that plays
out probably not
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what on earth is that
ed Titus Vibrio never heard of it
although I could kind of work out what
it does
Fieldy gives me what's exactly got food
poisoning but also enter means anything
in your gut itis means inflammation
Vibrio no idea what that means but this
is where I can learn things for
themselves at work so a bacteria that
normally resides in seawater so probably
not something that caused my food
poisoning yeah it is did Europe from
that sausage consuming seawater
contaminated by this bacteria can lead
to contagious enteritis Vibrio food
poisoning and company by severe stomach
pain and alike well card it makes sense
so you see these bacteria have these
tails as well we saw that in the first
episode these are the flagella
so these basic sensory organs and
involved in motility as well so how the
bacteria can get around
[Music]
so Jesus do that can you stop
yeah that's absolutely right generally
when we have an infection of the gut the
gut is in a way considered outside of
the body we have lots of defensive
mechanisms to stop anything getting into
the bloodstream
so as this t-cell is saying here we
wouldn't expect anything in the gut
unless it's a real kind of severe thing
to then sort of spread in to the body so
we did not expect to see a bacteria eat
a neutrophils so in reality neutrophils
about ten times the size of a bacteria
so it's actually the neutrophil that's
more likely to phagocytose so eat the
bacteria although maybe this one's
particular big long because I don't know
much about it although in previous
episodes were obviously seeing the
bacteria do have lots of kind of
defensive mechanisms so maybe this is
just demonstrating that in a different
way you don't sit I sense you are oh you
know you should know what this annoys a
little not so kind okay look so here we
meet the basal Phil which is another
white blood cell to add to our family
let me draw him in so here is our basal
Phil no the basal feel is not something
I learned a lot about medical school
maybe that was just my training but no
way it belongs in our family tree it's
very closely related to the neutrophil
and the escena field that we saw before
and one other cell as well that we
briefly saw in this episode by just get
a chose to skip it and that is the
Marcel now these four cells make up the
granular sites
what does that mean it means they have
these granules in their cytoplasm so
these little pockets of chemicals
now the JA believe granular sites is
when they're activated so when something
around them triggers them off generally
by firing a receptor on the cell surface
their job is to D granulate and to
expel these chemicals from the cell so
if these cubes represent our granules
within the cell when the cell gets the
message it will release these chemicals
into the area in the case of basophils
this is saying like histamine and this
works on the blood vessels so this makes
the blood vessels dilate and makes them
more leaky which means that more blood
flows there and more cells leak out
therefore we get more immune cells to
the area so that all to do with
coordinating the immune response some of
these chemicals are also released in
degranulation are toxic chemicals things
like enzymes that help break down the
pathogens
[Music]
[Applause]
site
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that's not a bacteria obviously they put
an ad break no good teaser okay it's a
parasite that was probably a bit obvious
wasn't it cause it's that episode about
it's in a felt it's and I think
Zacchaeus I hope I'm saying that right
I've never heard of this type of
parasite I'm not really adding a lot TV
pathogens in this episode this is a
parasite found in marine animals so it
fits in with the seafood the seafood
source of the food poisoning before
because we had our enteritis and Vibrio
was also from in infected seafood also
accelerates the immune system when
humans consume a nice aqus infested
seafood raw in rare cases they can
invade the stomach and the lining of the
intestine so we talked about earlier
that normally infections are localized
within the gut and don't spread but in
the case of this parasite can spread
causing food poisoning accompanied by
severe stomach pain and vomiting so our
body's having this vomit response
because it wants to try and expel the
pathogen from the stomach get rid of the
stomach contents and I love this
depiction of the basophils this kind of
mystic spiritual cell it kind of goes
along with my lack of understanding of
its bit of a mystery to me what it does
I love how the Vaser feel when he's
talking about being sick refers to it as
a sea of health I will open the
forbidden door is exactly what it feels
like isn't it you get this real cloudy
head and this sort of deep feeling
inside and you kind of transcend onto
another level
the medical term though for being sick
we call emesis
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yeah
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so I preempted it but here they give a
nice explanation of emesis here and yes
there is an area of the brain called the
vomit center I always get goose pimples
at this bit cells at work whether you're
about to see the cell do its job that's
you know the action in it is is so good
but then when you think about this is
actually happening in the body all the
time lots of different white blood cell
types and you know combining with the
natural defenses of the body to try and
eradicate infection and keep you alive
it's pretty cool thing so yeah let's see
what the pills go in store for us
[Applause]
[Music]
cause thank you not that I keep
sincerity names Huestis a sauna suit the
skinny little cousin very good we talked
earlier about the neutrophils being a
lot bigger than the bacterial cells so
that's how they're able to engulf the
bacteria and digest it and we caught
Vega cytosis so therefore how are we
able to do with these kind of pathogens
like large parasites that are bigger
than ourselves how is are a sinner Phil
you know specialized in killing these
parasites that let me show you
so we've met some of these pathogens
already but let me just recap them so we
have a virus which are incredibly small
and not living things they just have a
sort of protein capsule and a little bit
of a genetic material in them around
about a hundred times the size of a
virus we have a bacterial cell these are
living things but they've got very basic
area of genetic material that we call
the nucleoid and they have a cell wall
and other things that we've seen before
like pill I and a flat yellow roughly
two to three times bigger than bacterial
cells we have fungal cells and these are
the first example of eukaryotic cells
that means they have a true nucleus with
genetic material and also more developed
things called organelles which helped
run the cell now this isn't quite to
scale but all of these things can easily
be if a Gosai toast by one of our white
blood cells now we'll get on to some
slightly bigger organisms one group we
called the protozoa so these are kind of
single cellular organisms roughly about
ten times the size of bacteria again
because a eukaryotic they've got a true
nucleus and true organelles now these
kind of vary in size an example of one
of these would be something like malaria
and then on the other sort of extreme
end of size of parasites is a multi
cellular organism so something like
tapeworms and liver flukes and the a
nice a kiss so that's the parasite we
saw in cells at work and these
much more like traditional animals that
we are used to rather than these sort of
small microorganisms so let's say this
is kind of a liver fluke here it's got a
mouth and an anus and a kind of sucker
here so it can attach onto things now we
can see the problem our white blood
cells are no longer big enough to Faygo
Saito's these large pathogens so what do
we do about it well this is where
degranulation comes in what we talked
about earlier so the sinner fill this is
our acid in a fill here we'll attach on
to the side of the parasite just like we
saw in cells of work actually and you
know that pitchfork or that represents
the degranulation so release all these
toxic chemicals so we have here these
toxic chemicals that make up these
pocket granules that we talked about
earlier and they once they stick on they
become activated and this releases these
toxic chemicals onto the parasite and
digests the parasite
[Music]
Hey boom that's one dead parasite so
there we have it another cracking
episode of cells at work we learn about
emesis it's in the Phils parasites
granulocytes and loads of other stuff
all wrapped up into this lovely story
thank you so much for joining me and
being part of this series I've been
blown away by all the support if if you
enjoyed it leave a comment below if
there's anything I missed again let me
know in a comment below thanks again for
watching and I'll see you guys soon
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