have you ever realized that it your
deepest most inner core you're not
really you well think about it
the minute you eat something and swallow
it and it passes in through your
gastrointestinal tract that's the
external environment that food that you
just took in was a part of the outside
world and the tract that it's going to
follow in through from your mouth till
the point that you expel it in the
bathroom is actually not you that's the
external environment how weird is that
so in this video we're going to do an
overview of the gastrointestinal tract
I'll talk about each of the individual
parts and what their main overall
functions are and then in subsequent
videos I'll go through each of these
individual parts and give a more
detailed explanation of how they do what
they do alright so starting off of
course the first place our food is ever
going to go to is our mouth or the oral
cavity the main functions that we have
achieved in the mouth include chewing
the Morse elation of food also very
important is hydrolysis as you might
recall from biochemistry hydrolysis is
just the enzymatic digestion or the
enzymatic breakdown where chewing is the
physical breakdown hydrolysis is the
enzyme assisted breakdown of food and so
as we break down food the goal here is
to make what's called a bolus just a
sphere of digested food that can then be
swallowed and passed on into our next
structure and so after we swallow the
food where do you think it goes this guy
right here and that's the e so Vegas the
esophagus and this I think is one of the
more boring parts of the GI tract
because all we do here is just propel
our bolus we just pass it on down to the
next guy we don't really even do
anything to it kind of boring but the
next guy is a little more exciting now
we get to the stomach a lot of action
going on in the stomach one of my
favorite parts of the GI tract the
stomach is its responsible for multiple
things including churning which is a lot
like chewing
except that there are sort of more
dimensions of contraction affecting the
food and breaking it down we also have
hydrolysis going on here the enzyme
assisted breakdown of food in addition
to that you can store food in your
stomach if it's not time to pass it on
to the next component of your GI tract
and the overall goal here is to make
what's called chyme so we take our bolus
and we sort of melted down per se into
this more fluid type of substance that
we can pass on to our intestines so
we're moving on now to our intestines so
starting from about this point right
here we get our duodenum and then this
kind of you know circulates around here
and then we end up at this point
everything in between I'll draw it way
out here I'm just going to group
together for right now as the small
intestine the small intestine and there
are three parts to this and we'll talk
about that in a subsequent video but the
main functions that we achieve here are
hydrolysis and also the absorption of
nutrients and notice this is kind of the
first part of your GI tract that you're
finally taking in some of the breakdown
food products and using them for
nutrition to make other products in your
body great so now that we've gone
through the small intestine what do you
think shows up next so starting from
after the small intestine ended all the
way through this lined structure right
here
we are going to be passing through the
large intestine the large intestine do
you guys remember the other name for the
large intestine starts with a C if you
said : absolutely right so the colon is
also one of the more boring parts of the
GI tract so really all we have going on
here is absorption but not of nutrients
per se more like things like water or
ions or vitamin K just things like that
are absorbed in the large intestine so
not very high-yield place for acquiring
nutrients and then after that
we're going to pass food on to this
structure here and this is called the
rectum the rectum kind of like the
stomach of the GI tract the rectum
serves for storage we hold on to our
processed food if we can call it that
anymore at this point and it's held
there until we deem it an appropriate
time to expel the food and so when it's
time to expel the food it'll come out
through the anus through expulsion
expulsion so those are all the key
components of our gastrointestinal tract
there are some other accessory organs
that are involved here in digestion and
we'll all have videos to talk about them
as well those include things like the
liver the gallbladder the pancreas and
those will come up in subsequent videos