Digestive System 7- Large intestine

Digestive System 7- Large intestine


– We made it
through the small intestine, where most of our chemical
digestion has happened and most of
our absorption has happened. And now we enter a structure that is structurally
much different. If you look at it,
there is no question. We are somewhere new. We are no longer
in Kansas anymore, because we exit the ileum and we
enter this giant green thing, which is the large intestine. Another name
for the large intestine, that’s the intestine,
is the colon. And just like the small
intestine has multiple parts, the large
intestine has multiple parts. Food travels from the ileum
into the first part of the large intestine,
which is the cecum. So from the large intest– no, from the ileum
we go into the cecum. The cecum is
like this little pouch. And because the ileum is so long
and the jejunum is so long, basically, if I’m going to– if we are going
to expect that you know from a gross anatomy perspective what part of the small
intestine are we in, if you are close
to the large intestine, if you are close to the cecum, then you know that you
are in the ileum. The cecum, this little pouch, the appendix actually
hangs off of the cecum. And the appendix is literally this little wormy thing
that hangs off of the pouch. Now, this is awesome
because the cecum, food in the cecum, travels upward
in the ascending colon. And then it travels across,
in the transverse colon, and then it travels down
in the descending colon. What?
How nice is that? And then it travels through kind
of an S-shaped space, no, tube, and that S-shaped
tube is called the sigmoid. Doesn’t that sound
like a curly word? The sigmoid colon. And then rectum means straight. So, the tube sigmoids,
and then it straightens out, and that is your rectum.
The rectum is straight. And the rectum is where, dude,
we’re on our way out. The only thing that is found
in the rectum is stuff that is going
to be gone shortly. And you pass through the anus,
you do? No, goodness.
Holy cow. Food passes from the rectum out. It’s not even food anymore.
What is it? It’s leftovers
that your body is, like, dude, I don’t even
want that stuff anymore, and it passes through your anus
and out into your toilet. Now, what happened to this food?
It really is food. It is what you just ate. That is your meal. The feces that you
produced is stuff that was literally never
inside your body. It never–you took everything
you want out of it, and whatever is left over
is going in the toilet. And it must pass
through your anus. Now, most of the absorption of nutrients happens
in the small intestine. There is some nutrient
absorption that happens in the large
intestine, but most of it
is water absorption. So the function
of the large intestine really is to absorb water. We’ve got
some important nutrients that are produced by bacteria. What?
Bacteria make vitamin K in your large intestine,
and then you absorb that, which, that’s awesome. So, there is some absorption
of important stuff that’s happening
in your large intestine, but for the most
part it is water. And then you can pack down
your little poopies, and then they
come out your anus. That’s it. Dude, we’re done
with the large intestine. Let’s talk about our
accessory structures because those guys are cool.

3 thoughts on “Digestive System 7- Large intestine

  1. isn't colon a part of large intestine…..u know like cecum, colon , rectum??.. would u please clarify this doubt…

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