If we look at the wall
structure of the large intestine
then we can see we have this band
of longitudinal muscle. But again importantly
it really is just associated with taenia
we don't have that complete band of
longitudinal muscle. Remember those three
of those taeina coli. But we also have the
circular layer which
is consistent around them.
If we look at the structure of the
large intestine, it's wall, we see that it
has a larger diameter than the small intestine.
But the wall is actually thinner
the wall is actually a lot thinner than
the small intestine. There is an absence of villi
so we don't have this big surface area
which is enhanced by the villi in the
small intestine. This is indicative of the fact
that it is not actually been that active
in absorption. It is just absorbing
some water and vitamin. Its main priority
is to store faeces until
defecation and that's why we have
these distinctive intestinal glands
which are located in the wall
of the large intestine. And within these
glands there is an abundance of goblet cells
and these produces lots of, lots of, lots of
and lots of mucus. Because the water is being
drown out from the faeces, they can
actually become quite dehydrated
dry. So we need to have some lubrication
via this mucus to allow the faeces
to pass through the large intestine
and ultimately be removed.
This is a picture of an actual piece
of large intestine which has a series
of little pouches and these are unusual.
Well we can see in this diagram
is we got a taenia coli here.
And we can actually make out
some little pouches which we can
see here. Some little bulging pouches
and these are called diverticuli.
These little pouches are not normally
occurring in the large intestine. But they
are bulging out from the wall
of the large intestine. Now
diverticulosis is a series of
these out-pouchings along the wall of
colon and it usually found in the sigmoid colon.
The result of changes in
pressure with defaecation
now what the likely cause of
them is the lack of fiber within
your diet. If you did not have a
high level of fiber within your diet
then a lot of the water from
the faeces is absorbed
If you have some fiber in your diet, which
isn't really digested, that's going to hold onto
the water and make your faeces softer.
Because you know you have a high level of
water in your faeces that can be easily
removed; because, its quite soft and the flow
can be relatively smooth. If there
is a lack of fiber, a lot of the water
is removed which makes the
stools hard. For these to be defaecated,
for these to be removed, you have to
increase intra-abdominal pressure to such an extent
that you are physically forcing the
faeces away, they're not allowed to just glide
away. This can change the pressure
within the large intestine and resulting in these
little out-pouchings occurring.
If we have these outpouchings,
and then they become occluded, they can lead
to infections and inflammations and
with this inflammation, you can have
diverticulitis where they become inflamed.
If they end up bleeding, they can be
quite painful and then you can develop having
blood in your stools. So diverticulosis leading
to the diverticulitis can be quite serious condition.